Codeword determination for acknowledgement information

ABSTRACT

Methods and apparatus are provided for a base station to enable a user equipment (UE) configured for operation with carrier aggregation over a number of cells to determine cells and transmission time intervals (TTIs) where the base station transmits data information to the UE and for the UE to determine and arrange corresponding acknowledgement information in a codeword.

CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY

The present application claims priority under 35 U.S.C. § 119(e) to U.S.Provisional Patent Application Ser. No. 62/143,569 filed Apr. 6, 2015;U.S. Provisional Patent Application Ser. No. 62/145,267 filed Apr. 9,2015; U.S. Provisional Patent Application Ser. No. 62/172,306 filed Jun.8, 2015; and U.S. Provisional Patent Application Ser. No. 62/144,684filed Apr. 8, 2015. The contents of the above-identified patentdocuments are incorporated herein by reference.

TECHNICAL FIELD

The present application relates generally to wireless communicationsand, more specifically, to determining a codeword of acknowledgementinformation in carrier aggregation operation.

BACKGROUND

Wireless communication has been one of the most successful innovationsin modern history. Recently, the number of subscribers to wirelesscommunication services exceeded five billion and continues to growquickly. The demand of wireless data traffic is rapidly increasing dueto the growing popularity among consumers and businesses of smart phonesand other mobile data devices, such as tablets, “note pad” computers,net books, eBook readers, and machine type of devices. In order to meetthe high growth in mobile data traffic and support new applications anddeployments, improvements in radio interface efficiency and coverage isof paramount importance.

SUMMARY

This disclosure provides methods and apparatus for determining acodeword of acknowledgement information in carrier aggregationoperation.

In a first embodiment, a method includes receiving control signalingthat conveys downlink control information (DCI) formats. Each of the DCIformats indicates scheduling for either a reception for a physicaldownlink shared channel (PDSCH) or a release for a semi-persistentlyscheduled (SPS) PDSCH in a transmission time interval (TTI) from anumber of TTIs and on a cell from a number of cells. Each TTI has a TTIindex and each cell has a cell index. Each of the DCI formats isassociated with a cell index and with a TTI index for a respective PDSCHreception or SPS PDSCH release. Each of the DCI formats, when receivedin a first search space, includes a value for a counter downlinkassignment indicator (DAI) field that counts DCI formats, first acrosscells from the number of cells according to an ascending cell index andthen across TTIs from the number of TTIs according to an ascending TTIindex, until the index of the TTI and the index of the cell associatedwith the DCI format. Each of the DCI formats, when received in a secondsearch space, includes a value for a total DAI field that counts DCIformats across all cells and across TTIs from the number of TTIsaccording to an ascending TTI index until the index of the TTIassociated with the DCI format. The method additionally includesgenerating acknowledgement information bits in response to receiving thePDSCHs or the SPS PDSCH release. The method also includes transmittingthe acknowledgement information bits.

In a second embodiment, a UE includes a receiver, a controller, and atransmitter. The receiver is configured to receive control signalingthat conveys DCI formats. Each of the DCI formats indicates schedulingfor either a reception for a PDSCH or a release for a SPS PDSCH in a TTIfrom a number of TTIs and on a cell from a number of cells. Each TTI hasa TTI index and each cell has a cell index. Each of the DCI formats isassociated with a cell index and with a TTI index for a respective PDSCHreception or SPS PDSCH release. Each of the DCI formats, when receivedin a first search space, includes a value for a counter DAI field thatcounts DCI formats, first across cells from the number of cellsaccording to an ascending cell index and then across TTIs from thenumber of TTIs according to an ascending TTI index, until the index ofthe TTI and the index of the cell associated with the DCI format. EachDCI format, when received in a second search space, includes a value fora total DAI field that counts DCI formats across all cells and acrossTTIs from the number of TTIs according to an ascending TTI index untilthe index of the TTI associated with the DCI format. The controller isconfigured to generate acknowledgement information bits in response tothe reception of the PDSCHs or the SPS PDSCH release. The transmitter isconfigured to transmit the acknowledgement information bits.

In a third embodiment, a base station includes a transmitter and areceiver. The transmitter is configured to transmit control signalingthat conveys DCI formats. Each of the DCI format indicates schedulingfor either a transmission for a PDSCH or a release for a SPS PDSCH in aTTI from a number of TTIs and on a cell from a number of cells. Each TTIhas a TTI index and each cell has a cell index. Each of the DCI formatsis associated with a cell index and with a TTI index for a respectivePDSCH transmission or SPS PDSCH release. Each of the DCI formats, whentransmitted in a first search space, includes a value for a counter DAIfield that counts DCI formats, first across cells from the number ofcells according to an ascending cell index and then across TTIs from thenumber of TTIs according to an ascending TTI index, until the index ofthe TTI and the index of the cell associated with the DCI format. Eachof the DCI formats, when transmitted in a second search space, includesa value for a total DAI field that counts DCI formats across all cellsand across TTIs from the number of TTIs according to an ascending TTIindex until the index of the TTI associated with the DCI format. Thereceiver is configured to receive acknowledgement information bits inresponse to the transmission of the PDSCHs or of the SPS PDSCH release.

Before undertaking the DETAILED DESCRIPTION below, it may beadvantageous to set forth definitions of certain words and phrases usedthroughout this patent document. The term “couple” and its derivativesrefer to any direct or indirect communication between two or moreelements, whether or not those elements are in physical contact with oneanother. The terms “transmit,” “receive,” and “communicate,” as well asderivatives thereof, encompass both direct and indirect communication.The terms “include” and “comprise,” as well as derivatives thereof, meaninclusion without limitation. The term “or” is inclusive, meaningand/or. The phrase “associated with,” as well as derivatives thereof,means to include, be included within, interconnect with, contain, becontained within, connect to or with, couple to or with, be communicablewith, cooperate with, interleave, juxtapose, be proximate to, be boundto or with, have, have a property of, have a relationship to or with, orthe like. The term “controller” means any device, system or part thereofthat controls at least one operation. Such a controller may beimplemented in hardware or a combination of hardware and software and/orfirmware. The functionality associated with any particular controllermay be centralized or distributed, whether locally or remotely. Thephrase “at least one of,” when used with a list of items, means thatdifferent combinations of one or more of the listed items may be used,and only one item in the list may be needed. For example, “at least oneof: A, B, and C” includes any of the following combinations: A, B, C, Aand B, A and C, B and C, and A and B and C.

Moreover, various functions described below can be implemented orsupported by one or more computer programs, each of which is formed fromcomputer readable program code and embodied in a computer readablemedium. The terms “application” and “program” refer to one or morecomputer programs, software components, sets of instructions,procedures, functions, objects, classes, instances, related data, or aportion thereof adapted for implementation in a suitable computerreadable program code. The phrase “computer readable program code”includes any type of computer code, including source code, object code,and executable code. The phrase “computer readable medium” includes anytype of medium capable of being accessed by a computer, such as readonly memory (ROM), random access memory (RAM), a hard disk drive, acompact disc (CD), a digital video disc (DVD), or any other type ofmemory. A “non-transitory” computer readable medium excludes wired,wireless, optical, or other communication links that transporttransitory electrical or other signals. A non-transitory computerreadable medium includes media where data can be permanently stored andmedia where data can be stored and later overwritten, such as arewritable optical disc or an erasable memory device.

Definitions for other certain words and phrases are provided throughoutthis disclosure. Those of ordinary skill in the art should understandthat in many if not most instances such definitions apply to prior aswell as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals represent like parts:

FIG. 1 illustrates an example wireless communication network accordingto this disclosure;

FIG. 2 illustrates an example UE according to this disclosure;

FIG. 3 illustrates an example eNB according to this disclosure;

FIG. 4 illustrates an example UL SF structure for PUSCH transmission orPUCCH transmission according to this disclosure;

FIG. 5 illustrates an example encoding and modulation process for UCIaccording to this disclosure;

FIG. 6 illustrates an example demodulation and decoding process for UCIaccording to this disclosure;

FIG. 7 illustrates an example UE transmitter for a PUCCH having a sameSF structure as a PUSCH according to this disclosure;

FIG. 8 illustrates an example eNB receiver for a PUCCH having a same SFstructure as a PUSCH according to this disclosure;

FIG. 9 illustrates a structure for a PUCCH format 3 over one SF slot fortransmission of HARQ-ACK information according to this disclosure;

FIG. 10 illustrates a UE transmitter block diagram for HARQ-ACKinformation using a PUCCH format 3 according to this disclosure;

FIG. 11 illustrates an eNB receiver block diagram for receiving HARQ-ACKinformation in a PUCCH format 3 according to this disclosure;

FIG. 12 illustrates a communication using CA according to thisdisclosure;

FIG. 13 illustrates a selection by a UE of a PUCCH format based on anassociated HARQ-ACK codeword size according to this disclosure;

FIG. 14 illustrates a functionality of a cell-domain DAI that includes arelative counter DAI and a forward counter DAI according to thisdisclosure;

FIG. 15 illustrates a functionality of a cell-domain DAT that includes arelative counter DAI and a total counter DAI according to thisdisclosure;

FIG. 16 illustrates a generation of HARQ-ACK information bits by a UEbased on a counter DAI field and either on a forward DAI field or on atotal DAI field according to this disclosure;

FIG. 17 illustrates a procedure for a UE to transmit and for an eNB todetect an HARQ-ACK information payload according to this disclosure;

FIG. 18 illustrates a combined functionality of a relative counter DAIand of a total counter DAI according to this disclosure;

FIG. 19 illustrates a determination and arrangement for a HARQ-ACKinformation payload using a counter DAI for a TDD system according tothis disclosure;

FIG. 20 illustrates a determination and arrangement for a HARQ-ACKinformation payload using a value of a counter DAI and a value of atotal DAI for a TDD system according to this disclosure;

FIG. 21 illustrates a determination and arrangement for a HARQ-ACKinformation payload when a DL DCI format is transmitted in a CSS for aTDD system according to this disclosure;

FIG. 22 illustrates a procedure for an eNB to detect an HARQ-ACKcodeword in a PUCCH using a CRC check or, in case of multiple possiblePUCCH formats, a DTX detection for some of the PUCCH formats accordingto this disclosure;

FIG. 23 illustrates a determination and arrangement for a HARQ-ACKinformation payload transmission in a PUSCH transmission using a counterDAI value in a DL DCI format scheduling a PDSCH transmission and a DAIvalue in an UL DCI format scheduling a PUSCH transmission for a FDDsystem according to this disclosure;

FIG. 24 illustrates a method for a UE to transmit HARQ-ACK informationby indicating a number of detected DL DCI formats according to thisdisclosure;

FIG. 25 illustrates a determination and arrangement of HARQ-ACKinformation in a PUSCH using a counter DAI value and a total DAI valuein a DL DCI format scheduling a PDSCH transmission and a DAI value in anUL DCI format scheduling a PUSCH transmission for a TDD system accordingto this disclosure; and

FIG. 26 illustrates a determination and arrangement for a HARQ-ACKinformation payload transmission in a PUSCH using a counter DAI value ina DL DCI format scheduling a PDSCH transmission and a DAI value in an ULDCI format scheduling a PUSCH transmission for a TDD system according tothis disclosure.

DETAILED DESCRIPTION

FIGS. 1 through 26, discussed below, and the various embodiments used todescribe the principles of the present disclosure in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of the disclosure. Those skilled in the artwill understand that the principles of the present disclosure may beimplemented in any suitably arranged wireless communication system.

The following documents and standards descriptions are herebyincorporated by reference into the present disclosure as if fully setforth herein: 3GPP TS 36.211 v12.4.0, “E-UTRA, Physical channels andmodulation” (REF 1); 3GPP TS 36.212 v12.3.0, “E-UTRA, Multiplexing andChannel coding” (REF 2); 3GPP TS 36.213 v12.4.0, “E-UTRA, Physical LayerProcedures” (REF 3); 3GPP TS 36.331 v12.4.0, “E-UTRA. Radio ResourceControl (RRC) Protocol Specification” (REF 4); U.S. Pat. No. 8,588,259,entitled “Multiplexing Large Payloads of Control Information from UserEquipments” (REF 5); and U.S. Pat. No. 8,837,450, entitled “Transmissionof HARQ Control Information from a User Equipment for Downlink CarrierAggregation” (REF 6).

One or more embodiments of the present disclosure relate to determininga codeword of acknowledgement information in carrier aggregation (CA)operation. A wireless communication network includes a downlink (DL)that conveys signals from transmission points, such as base stations orenhanced NodeBs (eNBs), to UEs. The wireless communication network alsoincludes an uplink (UL) that conveys signals from UEs to receptionpoints, such as eNBs.

FIG. 1 illustrates an example wireless network 100 according to thisdisclosure. The embodiment of the wireless network 100 shown in FIG. 1is for illustration only. Other embodiments of the wireless network 100could be used without departing from the scope of this disclosure.

As shown in FIG. 1, the wireless network 100 includes an eNB 101, an eNB102, and an eNB 103. The eNB 101 communicates with the eNB 102 and theeNB 103. The eNB 101 also communicates with at least one InternetProtocol (IP) network 130, such as the Internet, a proprietary IPnetwork, or other data network.

Depending on the network type, other well-known terms may be usedinstead of “eNodeB” or “eNB,” such as “base station” or “access point.”For the sake of convenience, the terms “eNodeB” and “eNB” are used inthis patent document to refer to network infrastructure components thatprovide wireless access to remote terminals. Also, depending on thenetwork type, other well-known terms may be used instead of “userequipment” or “UE,” such as “mobile station,” “subscriber station,”“remote terminal,” “wireless terminal,” or “user device.” A UE may befixed or mobile and may be a cellular phone, a personal computer device,and the like. For the sake of convenience, the terms “user equipment”and “UE” are used in this patent document to refer to remote wirelessequipment that wirelessly accesses an eNB, whether the UE is a mobiledevice (such as a mobile telephone or smart-phone) or is normallyconsidered a stationary device (such as a desktop computer or vendingmachine).

The eNB 102 provides wireless broadband access to the network 130 for afirst plurality of user equipments (UEs) within a coverage area 120 ofthe eNB 102. The first plurality of UEs includes a UE 111, which may belocated in a small business (SB); a UE 112, which may be located in anenterprise (E); a UE 113, which may be located in a WiFi hotspot (HS); aUE 114, which may be located in a first residence (R); a UE 115, whichmay be located in a second residence (R); and a UE 114, which may be amobile device (M) like a cell phone, a wireless laptop, a wireless PDA,or the like. The eNB 103 provides wireless broadband access to thenetwork 130 for a second plurality of UEs within a coverage area 125 ofthe eNB 103. The second plurality of UEs includes the UE 115 and the UE114. In some embodiments, one or more of the eNBs 101-103 maycommunicate with each other and with the UEs 111-116 using 5G, LTE,LTE-A, WiMAX, or other advanced wireless communication techniques.

Dotted lines show the approximate extents of the coverage areas 120 and125, which are shown as approximately circular for the purposes ofillustration and explanation only. It should be clearly understood thatthe coverage areas associated with eNBs, such as the coverage areas 120and 125, may have other shapes, including irregular shapes, dependingupon the configuration of the eNBs and variations in the radioenvironment associated with natural and man-made obstructions.

As described in more detail below, various components of the network 100(such as the eNBs 101-103 and/or the UEs 111-116) support the adaptationof communication direction in the network 100 and support transmissionor reception of acknowledgement information in CA operation.

Although FIG. 1 illustrates one example of a wireless network 100,various changes may be made to FIG. 1. For example, the wireless network100 could include any number of eNBs and any number of UEs in anysuitable arrangement. Also, the eNB 101 could communicate directly withany number of UEs and provide those UEs with wireless broadband accessto the network 130. Similarly, each eNB 102-103 could communicatedirectly between them or with the network 130 and provide UEs withdirect wireless broadband access to the network 130. Further, the eNB101, 102, and/or 103 could provide access to other or additionalexternal networks, such as external telephone networks or other types ofdata networks.

FIG. 2 illustrates an example UE 114 according to this disclosure. Theembodiment of the UE 114 shown in FIG. 2 is for illustration only, andthe other UEs in FIG. 1 could have the same or similar configuration.However, UEs come in a wide variety of configurations, and FIG. 2 doesnot limit the scope of this disclosure to any particular implementationof a UE.

As shown in FIG. 2, the UE 114 includes an antenna 205, a radiofrequency (RF) transceiver 210, transmit (TX) processing circuitry 215,a microphone 220, and receive (RX) processing circuitry 225. The UE 114also includes a speaker 230, a processor 240, an input/output (I/O)interface (IF) 245, an input 250, a display 255, and a memory 260. Thememory 260 includes an operating system (OS) program 261 and one or moreapplications 262.

The RF transceiver 210 receives, from the antenna 205, an incoming RFsignal transmitted by an eNB or another UE. The RF transceiver 210down-converts the incoming RF signal to generate an intermediatefrequency (IF) or baseband signal. The IF or baseband signal is sent tothe RX processing circuitry 225, which generates a processed basebandsignal by filtering, decoding, and/or digitizing the baseband or IFsignal. The RX processing circuitry 225 transmits the processed basebandsignal to the speaker 230 (such as for voice data) or to the processor240 for further processing (such as for web browsing data).

The TX processing circuitry 215 receives analog or digital voice datafrom the microphone 220 or other outgoing baseband data (such as webdata, e-mail, or interactive video game data) from the processor 240.The TX processing circuitry 215 encodes, multiplexes, and/or digitizesthe outgoing baseband data to generate a processed baseband or IFsignal. The RF transceiver 210 receives the outgoing processed basebandor IF signal from the TX processing circuitry 215 and up-converts thebaseband or IF signal to an RF signal that is transmitted via theantenna 205.

The processor 240 can include one or more processors or other processingdevices and can execute the OS program 261 stored in the memory 260 inorder to control the overall operation of the UE 114. For example, theprocessor 240 could control the reception of forward channel signals andthe transmission of reverse channel signals by the RF transceiver 210,the RX processing circuitry 225, and the TX processing circuitry 215 inaccordance with well-known principles. In some embodiments, theprocessor 240 includes at least one microprocessor or microcontroller.

The processor 240 is also capable of executing other processes andprograms resident in the memory 260. The processor 240 can move datainto or out of the memory 260 as required by an executing process. Insome embodiments, the processor 240 is configured to execute theapplications 262 based on the OS program 261 or in response to signalsreceived from eNBs, other UEs, or an operator. The processor 240 is alsocoupled to the I/O interface 245, which provides the UE 114 with theability to connect to other devices such as laptop computers andhandheld computers. The I/O interface 245 is the communication pathbetween these accessories and the processor 240.

The processor 240 is also coupled to the input 250 (e.g., touchscreen,keypad, etc.) and the display 255. The operator of the UE 114 can usethe input 250 to enter data into the UE 114. The display 255 may be aliquid crystal display or other display capable of rendering text and/orat least limited graphics, such as from web sites. The display 255 couldalso represent a touch-screen.

The memory 260 is coupled to the processor 240. Part of the memory 260could include a control or data signaling memory (RAM), and another partof the memory 260 could include a Flash memory or other read-only memory(ROM).

As described in more detail below, the transmit and receive paths of theUE 114 (implemented using the RF transceiver 210, TX processingcircuitry 215, and/or RX processing circuitry 225) support transmissionof acknowledgement information in CA operation.

Although FIG. 2 illustrates one example of UE 114, various changes maybe made to FIG. 2. For example, various components in FIG. 2 could becombined, further subdivided, or omitted and additional components couldbe added according to particular needs. As a particular example, theprocessor 240 could be divided into multiple processors, such as one ormore central processing units (CPUs) and one or more graphics processingunits (GPUs). Also, while FIG. 2 illustrates the UE 114 configured as amobile telephone or smart-phone, UEs could be configured to operate asother types of mobile or stationary devices. In addition, variouscomponents in FIG. 2 could be replicated, such as when different RFcomponents are used to communicate with the eNBs 101-103 and with otherUEs.

FIG. 3 illustrates an example eNB 102 according to this disclosure. Theembodiment of the eNB 102 shown in FIG. 3 is for illustration only, andother eNBs of FIG. 1 could have the same or similar configuration.However, eNBs come in a wide variety of configurations, and FIG. 3 doesnot limit the scope of this disclosure to any particular implementationof an eNB.

As shown in FIG. 3, the eNB 102 includes multiple antennas 305 a-305 n,multiple RF transceivers 310 a-310 n, transmit (TX) processing circuitry315, and receive (RX) processing circuitry 320. The eNB 102 alsoincludes a controller/processor 325, a memory 330, and a backhaul ornetwork interface 335.

The RF transceivers 310 a-310 n receive, from the antennas 305 a-305 n,incoming RF signals, such as signals transmitted by UEs or other eNBs.The RF transceivers 310 a-310 n down-convert the incoming RF signals togenerate IF or baseband signals. The IF or baseband signals are sent tothe RX processing circuitry 320, which generates processed basebandsignals by filtering, decoding, and/or digitizing the baseband or IFsignals. The RX processing circuitry 320 transmits the processedbaseband signals to the controller/processor 325 for further processing.

The TX processing circuitry 315 receives analog or digital data (such asvoice data, web data, e-mail, or interactive video game data) from thecontroller/processor 325. The TX processing circuitry 315 encodes,multiplexes, and/or digitizes the outgoing baseband data to generateprocessed baseband or IF signals. The RF transceivers 310 a-310 nreceive the outgoing processed baseband or IF signals from the TXprocessing circuitry 315 and up-converts the baseband or IF signals toRF signals that are transmitted via the antennas 305 a-305 n.

The controller/processor 325 can include one or more processors or otherprocessing devices that control the overall operation of the eNB 102.For example, the controller/processor 325 could control the reception offorward channel signals and the transmission of reverse channel signalsby the RF transceivers 310 a-310 n, the RX processing circuitry 320, andthe TX processing circuitry 315 in accordance with well-knownprinciples. The controller/processor 325 could support additionalfunctions as well, such as more advanced wireless communicationfunctions. For instance, the controller/processor 325 could support beamforming or directional routing operations in which outgoing signals frommultiple antennas 305 a-305 n are weighted differently to effectivelysteer the outgoing signals in a desired direction. Any of a wide varietyof other functions could be supported in the eNB 102 by thecontroller/processor 325. In some embodiments, the controller/processor325 includes at least one microprocessor or microcontroller.

The controller/processor 325 is also capable of executing programs andother processes resident in the memory 330, such as an OS. Thecontroller/processor 325 can move data into or out of the memory 330 asrequired by an executing process.

The controller/processor 325 is also coupled to the backhaul or networkinterface 335. The backhaul or network interface 335 allows the eNB 102to communicate with other devices or systems over a backhaul connectionor over a network. The interface 335 could support communications overany suitable wired or wireless connection(s). For example, when the eNB102 is implemented as part of a cellular communication system (such asone supporting 5G, LTE, or LTE-A), the interface 335 could allow the eNB102 to communicate with other eNBs, such as eNB 103, over a wired orwireless backhaul connection. When the eNB 102 is implemented as anaccess point, the interface 335 could allow the eNB 102 to communicateover a wired or wireless local area network or over a wired or wirelessconnection to a larger network (such as the Internet). The interface 335includes any suitable structure supporting communications over a wiredor wireless connection, such as an Ethernet or RF transceiver.

The memory 330 is coupled to the controller/processor 325. Part of thememory 330 could include a RAM, and another part of the memory 330 couldinclude a Flash memory or other ROM.

As described in more detail below, the transmit and receive paths of theeNB 102 (implemented using the RF transceivers 310 a-310 n, TXprocessing circuitry 315, and/or RX processing circuitry 320) supportreception of acknowledgement information in CA operation.

Although FIG. 3 illustrates one example of an eNB 102, various changesmay be made to FIG. 3. For example, the eNB 102 could include any numberof each component shown in FIG. 3. As a particular example, an accesspoint could include a number of interfaces 335, and thecontroller/processor 325 could support routing functions to route databetween different network addresses. As another particular example,while shown as including a single instance of TX processing circuitry315 and a single instance of RX processing circuitry 320, the eNB 102could include multiple instances of each (such as one per RFtransceiver).

In some wireless networks, DL signals can include data signals conveyinginformation content, control signals conveying DL control information(DCI), and reference signals (RS) that are also known as pilot signals.An eNB, such as eNB 102, can transmit one or more of multiple types ofRS, including UE-common RS (CRS), channel state information RS (CSI-RS),and demodulation RS (DMRS). A CRS can be transmitted over a DL systembandwidth (BW) and can be used by a UE, such as UE 114, to demodulatedata or control signals or to perform measurements. To reduce CRSoverhead, eNB 102 can transmit a CSI-RS with a smaller density in thetime domain than a CRS (see also REF 1 and REF 3). UE 114 can use eithera CRS or a CSI-RS to perform measurements and a selection can be basedon a transmission mode (TM) UE 114 is configured by eNB 102 for physicalDL shared channel (PDSCH) reception (see also REF 3). Finally, UE 114can use a DMRS to demodulate data or control signals. The eNB 102transmits data information to UE 114 through a PDSCH. The eNB 102transmits control information to UE 114 through a physical DL controlchannel (PDCCH) or through an enhanced PDCCH (EPDCCH). Unless otherwiseexplicitly mentioned, only PDCCH will be referred to in the followingbut the descriptions are also applicable for EPDCCH.

In some wireless networks, UL signals can include data signals conveyinginformation content, control signals conveying UL control information(UCI), and RS. A UE, such as UE 114, can transmit data information orUCI through a respective physical UL shared channel (PUSCH) or aphysical UL control channel (PUCCH) to an eNB, such as eNB 102. Thetransport channel transferring information from a PUSCH to higher layersis referred to as UL shared channel (UL-SCH). When UE 114 simultaneouslytransmits data information and UCI, UE 114 can multiplex both in a PUSCHor simultaneously transmit data information and possibly some UCI in aPUSCH and transmit some or all UCI in a PUCCH. UCI can include hybridautomatic repeat request acknowledgement (HARQ-ACK) informationindicating correct or incorrect detection of data transport blocks (TBs)in respective PDSCHs, scheduling request (SR) information indicating toeNB 102 whether UE 114 has data in its buffer, and channel stateinformation (CSI) enabling eNB 102 to select appropriate parameters forPDSCH or PDCCH transmissions to UE 114. HARQ-ACK information can includea positive acknowledgement (ACK) in response to a correct PDCCH or dataTB detection, a negative acknowledgement (NACK) in response to incorrectdata TB detection, and an absence of PDCCH detection (DTX) that can beimplicit or explicit. A DTX can be implicit when UE 114 does nottransmit a HARQ-ACK signal. It is also possible to represent NACK andDTX with a same NACK/DTX state in the HARQ-ACK information (see also REF3).

UL RS can include DMRS and sounding RS (SRS). UE 114 transmits a DMRSonly in a BW of a respective PUSCH or PUCCH and eNB 102 can use a DMRSto demodulate information in a PUSCH or PUCCH. UE 114 transmits a SRS inorder to provide eNB 102 with a UL CSI (see also REF 2 and REF 3). ADMRS is constructed by a constant amplitude zero autocorrelation (CAZAC)sequence such as a Zadoff-Chu (ZC). UE 114 applies a cyclic shift (CS)and an orthogonal covering code (OCC) to a DMRS transmission in the twoslots of a SF.

The eNB 102 can schedule a PDSCH transmission to UE 114 eitherdynamically, by transmitting a DL DCI format in a PDCCH, orsemi-statically by RRC signaling. The eNB 102 can schedule a PUSCHtransmission from UE 114 either dynamically, by transmitting an UL DCIformat in a PDCCH, or semi-statically by RRC signaling. DCI formats canalso provide other functionalities (see also REF 2). For example, a DCIformat 3/3A can be used to convey to a group of UEs respective powercontrol commands for adjusting a respective PUSCH transmission power ora PUCCH transmission power. UE 114 detects a PDCCH conveying a DCIformat through decoding operation in a common search space (CSS), suchas for a DCI format 3/3A, or in a UE-specific search space (USS) seealso REF 3. For some DCI formats, such as a DCI format 1A, a respectivePDCCH can be transmitted either in a CSS or in a USS. An EPDCCH can betransmitted only in a USS (see also REF 3).

A transmission time interval (TTI) for DL signaling or for UL signalingis one subframe (SF). For example, a SF duration can be one millisecond(msec). A unit of 10 SFs, indexed from 0 to 9, is referred to as asystem frame. In a time division duplex (TDD) system, a communicationdirection in some SFs is in the DL, and a communication direction insome other SFs is in the UL.

FIG. 4 illustrates an example UL SF structure for PUSCH transmission orPUCCH transmission according to this disclosure. The embodiment of theUL SF structure shown in FIG. 4 is for illustration only. Otherembodiments could be used without departing from the scope of thepresent disclosure.

UL signaling can use Discrete Fourier Transform Spread OFDM(DFT-S-OFDM). An UL SF 410 includes two slots. Each slot 420 includesN_(symb) ^(UL) symbols 430 where UE 114 transmits data information, UCI,or RS including one symbol per slot where UE 114 transmits DMRS 440. Atransmission BW includes frequency resource units that are referred toas resource blocks (RBs). Each RB includes N_(sc) ^(RB) (virtual)sub-carriers that are referred to as resource elements (REs). Atransmission unit of one RB over one slot is referred to as a physicalRB (PRB) and transmission unit of one RB over one SF is referred to as aPRB pair. UE 114 is assigned M_(PUXCH) RBs for a total of M_(sc)^(PUXCH)=M_(PUXCH)·N_(sc) ^(RB) REs 450 for a PUSCH transmission BW(‘X’=‘S’) or for a PUCCH transmission BW (‘X’=‘C’). A last SF symbol canbe used to multiplex SRS transmissions 460 from one or more UEs. Anumber of UL SF symbols available for data/UCI/DMRS transmission isN_(symb) ^(PUXCH)=2·(N_(symb) ^(UL)−1)·N_(SRS)·N_(SRS)=1 when a last SFsymbol supports SRS transmissions from UEs that overlap at leastpartially in BW with a PUXCH transmission BW; otherwise, N_(SRS)=0.Therefore, a number of total REs for a PUXCH transmission is M_(sc)^(PUXCH)·N_(symb) ^(PUXCH).

When the structure in FIG. 4 is used to transmit UCI (HARQ-ACK or P-CSIwith or without SR) in a PUCCH, there is no data information includedand UCI can be mapped over all REs except for REs used to transmit DMRSor SRS.

FIG. 5 illustrates an example encoding and modulation process for UCIaccording to this disclosure. The embodiment of the encoding processshown in FIG. 5 is for illustration only. Other embodiments could beused without departing from the scope of the present disclosure.

Upon determining that a number O_(UCI,0) of UCI bits is larger than apredetermined value, a UE 114 controller (not shown) provides the UCIbits 510 to a cyclic redundancy check (CRC) generator 520 that computesa CRC for the O_(UCI,0) UCI bits and appends O_(CRC) CRC bits, such as 8CRC bits, to the O_(UCI,0) UCI bits to result O_(UCI) UCI and CRC bits530. An encoder 540, such as a tail biting convolutional code (TBCC),encodes the output of O_(UCI) bits. A rate matcher 550 performs ratematching to allocated resources, followed by a scrambler 560 to performscrambling, a modulator 570 to modulate the encoded bits, for exampleusing QPSK, an RE mapper 580, and finally a transmitter for atransmission of a control signal 590.

FIG. 6 illustrates an example demodulation and decoding process for UCIaccording to this disclosure. The embodiment of the decoding processshown in FIG. 6 is for illustration only. Other embodiments could beused without departing from the scope of the present disclosure.

The eNB 102 receives a control signal 610 that is provided to a REdemapper 620 to perform RE demapping, a demodulator 630 to performdemodulation for a corresponding modulation scheme, a descrambler 640 toperform descrambling, a rate matcher 650 to perform rate matching, and adecoder 660, such as a TBCC decoder, to perform decoding and provideO_(UCI) UCI and CRC bits. A CRC extraction unit 670 separates O_(UCI,0)UCI bits 680 and O_(CRC) CRC bits 685, and a CRC checking unit 690computes a CRC check (whether a CRC checksum is zero for a positive CRCcheck or non-zero for a negative CRC check). When the CRC check passes(CRC checksum is zero), eNB 102 determines that the UCI is valid.

The eNB 102 can use a same transmitter structure for transmitting a DCIformat as UE 114 can use for transmitting UCI in FIG. 5. With respect toFIG. 5, UCI can be replaced by DCI format and a UE-specific scramblercan be replaced by a cell-specific scrambler. Similar, UE 114 can use asame receiver structure for receiving a DCI format as eNB 102 can usefor receiving UCI in FIG. 6. With respect to FIG. 6, UCI can be replacedby DCI format and a UE-specific descrambler can be replaced by acell-specific descrambler. Respective descriptions of an eNB 102transmitter structure and of a UE 114 receiver structure for a DCIformat are omitted for brevity.

FIG. 7 illustrates an example UE transmitter for a PUCCH having a sameSF structure as a PUSCH according to this disclosure. The embodiment ofthe transmitter shown in FIG. 7 is for illustration only. Otherembodiments could be used without departing from the scope of thepresent disclosure.

UCI bits from UE 114, such as O_(P-CSI) P-CSI information bits 705, whenany, and O_(HARQ-ACK) HARQ-ACK information bits 710, when any, but alsoa SR bit in a SF configured to UE 114 for SR transmission (not shown),are jointly encoded by encoder 720. The encoder can be a TBCC or turbocoding (TC) and CRC bits are included in each encoded codeword (see alsoREF 2). Encoded bits are subsequently modulated by modulator 730. Adiscrete Fourier transform (DFT) is obtained by DFT unit 740, REs 750corresponding to a PUCCH transmission BW are selected by selector 755,an inverse fast Fourier transform (IFFT) is performed by IFFT unit 760,an output is filtered and by filter 770, a processor applies a poweraccording to a power control procedure to power amplifier (PA) 780, anda transmitted 790 transmits a signal. Due to the DFT mapping, the REscan be viewed as virtual REs but are referred to as REs for simplicity.For brevity, additional transmitter circuitry such as digital-to-analogconverter, filters, amplifiers, and transmitter antennas as well asencoders and modulators for data symbols and UCI symbols are omitted.

A UE transmitter block diagram for data in a PUSCH can be obtained as inFIG. 7 by replacing HARQ-ACK information and CSI with data information.

FIG. 8 illustrates an example eNB receiver for a PUCCH having a same SFstructure as a PUSCH according to this disclosure. The embodiment of thereceiver shown in FIG. 8 is for illustration only. Other embodimentscould be used without departing from the scope of the presentdisclosure.

A received signal 810 is filtered by filter 820, a fast Fouriertransform (FFT) is applied by FFT unit 830, a selector unit 840 selectsREs 850 used by a transmitter, an inverse DFT (IDFT) unit applies anIDFT 860, a demodulator 870 demodulates the IDFT output using a channelestimate provided by a channel estimator (not shown), and finally adecoder 880 outputs O_(HARQ-ACK) HARQ-ACK information bits 890, whenany, and O_(P-CSI) CSI information bits 895, when any, and a SR bit (notshown), when any. Additional receiver circuitry such as a channelestimator, demodulators and decoders for data and UCI symbols are notshown for brevity.

An eNB receiver block diagram for data in a PUSCH can be obtained as inFIG. 8 by replacing HARQ-ACK information and CSI with data information.

For transmission of HARQ-ACK information payloads up to 22 bits, or forjoint transmission of HARQ-ACK information and single-cell CSI withtotal payload up to 22 bits, a PUCCH format 3 (see also REF 1 and REF 3)can be used and a payload of O_(HARQ-ACK) HARQ-ACK bits, or a payload ofO_(HARQ-ACK) HARQ-ACK bits and O_(CSI) CSI bits, can be encoded using ablock code. Considering for brevity in the following only the case ofHARQ-ACK bits, the block code can be a (32, O_(HARQ-ACK)) Reed-Mueller(RM) code.

FIG. 9 illustrates a structure for a PUCCH format 3 over one SF slot fortransmission of HARQ-ACK information according to this disclosure.

After encoding and modulation using respectively, for example, a (32,O_(HARQ-ACK)) RM code punctured to a (24, O_(HARQ-ACK)) RM code (seealso REF 2) and QPSK) modulation (not shown for brevity), a set of sameHARQ-ACK bits 910 is multiplied 920 with elements of an OCC 930 and issubsequently precoded by a DFT filter 940. For example, for 5 symbolsper slot used to transmit HARQ-ACK bits, the OCC has length 5 {OCC(0),OCC(1), OCC(2), OCC(3), OCC(4)} and can be either of {1, 1, 1, 1, 1}, or{1, exp(j2π/5), exp(j4π/5), exp(j6π/5), exp(j8π/5)}, or {1, exp(j4π/5),exp(j8π/5), exp(j2π/5), exp(j6π/5)}, or {1, exp(j6π/5), exp(j2π/5),exp(j8π/5), exp(j4π/5)}, or {1, exp(j8π/5), exp(j6π/5), exp(j4π/5),exp(j2π/5)}. The output is passed through an IFFT 950 and then mapped toa SF symbol 960. The previous operations are linear and their relativeorder can be inter-changed. As PUCCH format 3 is transmitted over onePRB pair, 24 encoded HARQ-ACK bits are transmitted in each slot and theyare mapped to 12 QPSK symbols in respective 12 REs. Same or differentHARQ-ACK bits can be transmitted in the second slot of a SF. RS is alsotransmitted in each slot to enable coherent demodulation of HARQ-ACKsignals. A RS is constructed from a length-12 CAZAC sequence (see alsoREF 1) 970 that is passed through an IFFT filter 980 and mapped toanother SF symbol 990. Multiplexing of RS from different UEs is achievedby using different CS of a same ZC sequence.

The structure in FIG. 9 can support a limited payload of HARQ-ACKinformation bits without incurring a large coding rate. For a HARQ-ACKpayload between 12 and 22 bits, a dual RM code can be used where amapping to successive elements of a DFT can alternate between elementsfrom an output of a first RM code and elements from an output of asecond RM code in a sequential manner (not shown for brevity see alsoREF 2).

FIG. 10 illustrates a UE transmitter block diagram for HARQ-ACKinformation using a PUCCH format 3 according to this disclosure. Theembodiment of the transmitter shown in FIG. 10 is for illustration only.Other embodiments could be used without departing from the scope of thepresent disclosure.

HARQ-ACK information bits 1005 are encoded and modulated 1010 and thenmultiplied 1020 with an OCC element 1025 for a respective DFT-S-OFDMsymbol. After DFT precoding by filter 1030, REs 1040 of an assigned PRBpair are selected 1050, an IFFT is performed 1060 and finally filtering1070 is applied and a signal is transmitted 1080. For brevity,additional transmitter circuitry such as RS transmission, CP insertion,digital-to-analog converter, analog filters, amplifiers, and transmitterantennas are not shown.

FIG. 11 illustrates an eNB receiver block diagram for receiving HARQ-ACKinformation in a PUCCH format 3 according to this disclosure. Theembodiment of the receiver shown in FIG. 11 is for illustration only.Other embodiments could be used without departing from the scope of thepresent disclosure.

A received signal 1110 is filtered by filter 1120, followed by FFTfilter 1130, RE selector 1140 selects REs 1150, filter 1160 applies anIDFT, multiplier 1170 multiplies an OCC element 1175 for a respectivePUCCH format 3 SF symbol, summer 1180 sums the outputs for PUCCH format3 SF symbols conveying HARQ-ACK signals over each slot, and demodulatorand decoder 1190 demodulate and decode, respectively the HARQ-ACKsymbols to obtain HARQ-ACK information bits 1195. Well known receiverfunctionalities such as analog filtering, CP extraction, and RSreception and channel estimation are not shown for brevity.

When UE 114 transmits O_(HARQ-ACK) HARQ-ACK information in a PUSCH thatconveys one data TB, UE 114 determines a number of coded modulationsymbols per layer Q′ for HARQ-ACK as being inversely proportional to amodulation and coding scheme (MCS) for data transmission, or when amodulation for HARQ-ACK information is fixed to QPSK, to a number ofcoded data symbols as in Equation 1 (see also REF 2)

$\begin{matrix}{{Q^{\prime} = {\min\left( {M_{RE}^{req},{4 \cdot M_{sc}^{PUSCH}}} \right)}}{where}} & (1) \\{{M_{RE}^{req} = \left\lceil \frac{O_{{HARQ}\text{-}{ACK}} \cdot M_{sc}^{{PUSCH}\text{-}{initial}} \cdot N_{symb}^{{PUSCH}\text{-}{initial}} \cdot \beta_{offset}^{PUSCH}}{\sum\limits_{r = 0}^{C - 1}K_{r}} \right\rceil},} & (2)\end{matrix}$β_(offset) ^(PUSCH) is configured by eNB 102 to UE 114, the remainingterms in Equation 2 are as defined in REF 2, and ┌ ┐ is a ceilingfunction that rounds a number to a smallest integer that is equal to orlarger than the number. When UE 114 transmits HARQ-ACK information in aPUSCH that conveys two data TBs, UE 114 determines a number of codedmodulation symbols per layer Q′ as described in REF 2 and additionaldescription is omitted for brevity.

In a TDD communication system, a communication direction in some SFs isin the DL, and a communication direction in some other SFs is in the UL.Table 1 lists indicative UL/DL configurations over a period of 10 SFsthat is also referred to as frame period. “D” denotes a DL SF, “U”denotes an UL SF, and “S” denotes a special SF that includes a DLtransmission field referred to as DwPTS, a guard period (GP), and a ULtransmission field referred to as UpPTS. Several combinations exist fora duration of each field in a special SF subject to the condition thatthe total duration is one SF (see also REF 1).

TABLE 1 TDD UL/DL configurations TDD DL-to-UL UL-DL Switch- Config-point SF number uration periodicity 0 1 2 3 4 5 6 7 8 9 0 5 msec D S U UU D S U U U 1 5 msec D S U U D D S U U D 2 5 msec D S U D D D S U D D 310 msec  D S U U U D D D D D 4 10 msec  D S U U D D D D D D 5 10 msec  DS U D D D D D D D 6 5 msec D S U U U D S U U D

In a TDD system, a HARQ-ACK signal transmission from UE 114 in responseto PDSCH receptions in multiple DL SFs can be transmitted in a same ULSF. A number M_(W) of DL SFs having associated HARQ-ACK signaltransmissions from UE 114 in a same UL SF is referred to as a DLassociation set or as a bundling window of size M_(W). A DL DCI formatscheduling a PDSCH transmission (or an SPS PDSCH release) includes a DLassignment index (DAI) field of two binary elements (bits) that providesa counter indicating a number of DL DCI formats, modulo 4, transmittedto UE 114 in a bundling window up to the SF of the DL DCI formatdetection (see also REF 2 and REF 3). Table 2 indicates DL SFs n−k,where kεK, that UE 114 transmits an associated HARQ-ACK signal in UL SFn. These DL SFs represent a bundling window for a respective UL SF.

TABLE 2 Downlink association set index K: {k₀, k₁, . . . k_(M−1)} TDDUL/DL Config- SF n uration 0 1 2 3 4 5 6 7 8 9 0 — — 6 — 4 — — 6 — 4 1 —— 7, 6 4 — — — 7, 6 4 — 2 — — 8, 7, — — — — 8, 7, — — 4, 6 4, 6 3 — — 7,6, 11 6, 5 5, 4 — — — — — 4 — — 12, 8, 6, 5, — — — — — — 7, 11 4, 7 5 —— 13, 12, 9, — — — — — — — 8, 7, 5, 4, 11, 6 6 — — 7 7 5 — — 7 7 —

A DAI field having a value V_(DAI) ^(DL) is included in each DL DCIformat scheduling a PDSCH transmission to UE 114. As eNB 102 cannotpredict whether or not eNB 102 will schedule a PDSCH transmission to UE114 in a future SF, V_(DAI) ^(DL) is a relative counter that isincremented in DL DCI formats scheduling PDSCH transmissions to UE 114in respective SFs of a bundling window. Then, for a DAI field thatincludes 2 bits, when UE 114 fails to detect up to 3 successive DL DCIformats scheduling PDSCH transmissions in respective SFs of a bundlingwindow but UE 114 detects a DL DCI format scheduling a PDSCHtransmission in a later SF of the bundling window, UE 114 can determinethat UE 114 failed to detect the up to 3 successive DL DCI formats andUE 114 can provide a NACK/DTX indication for HARQ-ACK information forthe up to 3 respective PDSCH transmissions. However, since V_(DAI) ^(DL)can only be a relative counter, when UE 114 fails to detect a DL DCIformat scheduling a PDSCH transmission in a last SF within a bundlingwindow, UE 114 has no means to identify the missed detection. Thisshortcoming can be circumvented by UE 114 providing HARQ-ACK informationto eNB 102 regarding outcomes of PDSCH receptions for all SFs of abundling window (see also REF 3).

One mechanism towards satisfying a demand for increased network capacityand data rates is network densification. This is realized by deployingsmall cells in order to increase a number of network nodes and theirproximity to UEs and provide cell splitting gains. As a number of smallcells increases and deployments of small cells become dense, a handoverfrequency and a handover failure rate can also significantly increase.By maintaining a RRC connection to the macro-cell, communication withthe small cell can be optimized as control-place (C-place)functionalities such as mobility management, paging, and systeminformation updates can be provided only by the macro-cell while asmall-cell can be dedicated for user-data plane (U-plane)communications. When a latency of a backhaul link between network nodes(cells) is practically zero, CA can be used as in REF 3 and schedulingdecisions can be made by a same eNB 102 and conveyed to each networknode. Moreover, UCI from UE 114 can be received at any network node,except possibly for nodes using unlicensed spectrum, and conveyed to eNB102 to facilitate a proper scheduling decision for UE 114.

FIG. 12 illustrates a communication using CA according to thisdisclosure.

UE 114 1210, communicates with a first cell 1220 corresponding to amacro-cell using a first carrier frequency f1 1230 and with a secondcell 1240 corresponding to a small cell over carrier frequency f2 1250.The first carrier frequency can correspond to a licensed frequency bandand the second carrier frequency can correspond to an unlicensedfrequency bad. The first cell and the second cell are controlled by eNB102 and are connected over a backhaul that introduces negligiblelatency.

When UE 114 is configured with CA operation over a first number of DLcells and over a second number of UL cells, PDCCH transmissions in a CSSare only on a primary DL cell and PUCCH transmissions are only on aprimary UL cell that is associated with the primary DL cell. Remaining,DL or UL, cells are referred to as secondary cells (see also REF 3). TheeNB 102 configures UE 114 with indexes for respective secondary cellswhile the primary cell has index 0 (see also REF 5). The abovefunctionalities can be parallelized for two cell groups (see also REF3).

When UE 114 is configured with CA operation with up to 5 DL cells,HARQ-ACK transmission on a PUCCH typically uses a PUCCH format 3 (seealso REF 1 and REF 3). For a TDD system, a PUCCH format 3 resource isdetermined from a transmission power control (TPC) command field in a DLDCI format with DAI value greater than ‘1’ or with DAI value equal to ‘1’ that is not the first DL DCI format that UE 114 detects within abundling window. UE 114 assumes that a same PUCCH resource index valueis transmitted in all DL DCI formats used to determine the PUCCHresource index value for a bundling window (see also REF 3). Afunctionality of a TPC command field in a DL DCI format with DAI valueequal to ‘1’ that is the first DL DCI format UE 114 detects in abundling window remains unchanged and provides a TPC command value forUE 114 to adjust a transmission power for the PUCCH format 3. In thismanner, a DAI field functions both as a counter of DL DCI formatstransmitted to UE 114 within a bundling window and as an indicatorwhether a TPC command field in a DL DCI format provides either a TPCcommand value or an indicator to one PUCCH resource from a set of PUCCHresources configured to UE 114 (ARI).

When a DL DCI format is conveyed by an EPDCCH, the DL DCI format alsoincludes a HARQ-ACK resource offset (HRO) field that either indicates aPUCCH resource for a PUCCH format 1a/1b transmission when the DL DCIformat schedules PDSCH on a primary cell or is set to zero when the DLDCI format schedules PDSCH on a secondary cell (see also REF 2 and REF3). Therefore, regardless of whether a DL DCI format scheduling a PDSCHtransmission is conveyed by a PDCCH or an EPDCCH, UE 114 cannot obtain aTPC command to transmit associated HARQ-ACK information in a PUCCH whenUE 114 does not detect a DL DCI format scheduling a PDSCH transmissionon a primary cell.

Typical CA operation supports up to 5 DL cells each with a maximum of 20MHz BW and, for UL/DL configuration 5 in TDD systems, for up to 2 DLcells (see also REF 3). This limitation on the number of DL cells thatUE 114 can support limits DL data rates due to a respective limitationin a total DL BW. With an availability of unlicensed spectrum where many20 MHz BW carriers can exist, a number of cells that can be configuredto UE 114 can become significantly larger than 5. Therefore, extendingsupport for CA beyond 5 DL cells can allow for more efficientutilization of available spectrum and improve DL data rates and serviceexperience for UE 114. A consequence from increasing a number of DLcells relates to a need to support larger UCI payloads. A new PUCCHformat that can accommodate large HARQ-ACK payloads or, in general,large UCI payloads can have a PUSCH-based structure (see also REF 5) anduse TBCC or TC to encode UCI.

As accommodating large HARQ-ACK payloads requires more UL resources orhigher transmission power, thereby increasing an associated overhead, orinterference and UE power consumption, it is beneficial for a UE to beprovided a capability to dynamically determine a HARQ-ACK payload, andaccordingly select a PUCCH format or resources according to apredetermined association with the UCI payload instead ofsemi-statically determine the HARQ-ACK payload based on a number ofconfigured DL cells and a configured PDSCH TM per each configured DLcell (see also REF 2 and REF 3). This can also be beneficial forreducing a resource overhead required for multiplexing HARQ-ACK in aPUSCH.

Embodiments of this disclosure provide mechanisms for a UE to determinea HARQ-ACK codeword. Embodiments of this disclosure also providemechanisms for a UE to select a PUCCH format or PUCCH resourcesaccording to a predetermined association with a HARQ-ACK codeword size.Embodiments of this disclosure additionally provide mechanisms forintroducing and utilizing DAI fields to determine and arrange HARQ-ACKinformation bits in a codeword for transmission in a PUCCH or in aPUSCH. Embodiments of this disclosure further provide mechanisms for aneNB to resolve possible error cases when a UE determines a HARQ-ACKcodeword.

When eNB 102 configures a parameters to UE 114, unless otherwiseexplicitly mentioned, the configuration is by higher layer signaling,such as RRC signaling. When eNB 102 dynamically indicates a parameter toUE 114, the indication is by physical layer signaling such as by a DCIformat.

In the following, for brevity and with a few exceptions, a SPS PDSCHtransmission or a DL DCI format indicating SPS PDSCH release is notexplicitly mentioned; UE 114 is assumed to include HARQ-ACK informationfor SPS PDSCH transmission or for a DL DCI format indicating SPS PDSCHrelease (see also REF 3). A DCI format indicating SPS PDSCH releaseincludes a same set of DAI fields as a DCI format scheduling a PDSCHtransmission. A DL DCI format refers to a DCI format scheduling a PDSCHtransmission or a SPS PDSCH release and an UL DCI format refers to a DCIformat scheduling a PUSCH transmission.

UE 114 is configured a group of cells for possible receptions ofrespective PDSCH transmissions (DL cells) for operation with CA. Eachcell in the group of cells is identified by a UE-specific cell indexthat eNB 102 informs to UE 114 through higher layer signaling. Forexample, UE 114 can be configured with a group of C cells and respectivecell indexes 0, 1, . . . , C−1. UE 114 generates one HARQ-ACKinformation bit in response to one DL DCI format detection when UE 114is configured with HARQ-ACK spatial domain bundling or, for each cellfrom the group of C cells, with a PDSCH TM that enables transmission ofonly one data TB. UE 114 generates two HARQ-ACK information bits inresponse to a DL DCI format detection when UE 114 is not configured withspatial domain bundling and UE 114 is configured with a PDSCH TM thatenables transmission of two data TB in at least one cell from the Ccells. For brevity, unless explicitly mentioned, following descriptionsconsider that UE 114 generates one HARQ-ACK information bit in responseto one DL DCI format detection.

The eNB 102 can also configure UE 114 with more than one cell for PUCCHtransmission (UL cell), such as for example two UL cells. PUCCHtransmission in a first UL cell is associated with a first group of DLcells and PUCCH transmission in a second UL cell is associated with asecond group of DL cells. UE 114 transmits a PUCCH on a primary cell ofa DL cell group. Unless otherwise explicitly noted, the descriptions inthis disclosure are with respect to one group of DL cells and can bereplicated per group of DL cells in case of more than one group of DLcells.

Selection of PUCCH Format or of PUCCH Resources for HARQ-ACKTransmission

UE 114 can select a PUCCH format or determine resources for a PUCCHformat transmission based on an actual HARQ-ACK payload instead of amaximum HARQ-ACK payload that is determined from a number of cells thatUE 114 is configured by eNB 102 and a configured PDSCH TM in each of theconfigured cells (see also REF 2 and REF 3).

UE 114 can use a first PUCCH format, such as PUCCH Format 3, to transmitup to a first number of HARQ-ACK information bits, such as 22 bits, anduse a second PUCCH format, such as one based on a PUSCH structure, totransmit a number of HARQ-ACK information bits larger than the firstnumber.

FIG. 13 illustrates a selection by a UE of a PUCCH format based on anassociated HARQ-ACK codeword size according to this disclosure.

UE 114 is configured for CA operation and determines a HARQ-ACKinformation payload 1310. As subsequently described, a determination canbe based on one or more DAI fields in respective one or more DL DCIformats scheduling respective one or more PDSCH transmissions (includingan SPS PDSCH release) to UE 114 in respective one or more cells from agroup of cells and, for a TDD system, in one or more SFs of a bundlingwindow. UE 114 examines whether the HARQ-ACK payload is larger than athreshold 1320. The threshold can be predetermined in a systemoperation, such as 11 bits or 22 bits, or can be configured to UE 114 byeNB 102. When the HARQ-ACK payload is not larger than the threshold, UE114 transmits the HARQ-ACK payload using a first PUCCH format 1330, suchas PUCCH format 3. When the HARQ-ACK payload is larger than thethreshold, UE 114 transmits the HARQ-ACK payload using a second PUCCHformat 1340 such as one having the PUSCH SF structure (see also REF 5).

DAI Design for a FDD System

For a FDD system, UE 114 can determine a HARQ-ACK payload (HARQ-ACKcodeword size) to transmit in a PUCCH based on a cell-domain DAI in DLDCI formats scheduling PDSCH transmissions or SPS PDSCH release inrespective cells that UE 114 detects, and on SPS PDSCH transmissions toUE 114, when any, in a same SF.

In a first approach, a value V_(DAI) ^(DL-C) of a cell-domain DAI fieldin a DL DCI format can be a relative counter for a cell where UE 114 isscheduled a PDSCH transmission where the relative counter incrementsaccording to an ascending order of a cell index. For example, when UE114 is configured with 32 cells for PDSCH transmissions, a DAI of 5 bitsin a DL DCI format can provide an index of a respective cell where UE114 is scheduled PDSCH transmission in a SF.

When UE 114 is configured for potential PDSCH transmissions in C cells,a cell-domain DAI size can be ┌log₂ C┐ bits. Alternatively, to have asame DL DCI format size regardless of a number of cells that UE 114 isconfigured PDSCH transmissions, a DAI size can be ┌log₂ C_(max)┐ bitswhere C_(max) is a maximum number of cells in a system operation, suchas 32 cells. When UE 114 is configured to receive PDSCH in C<C_(max)cells, UE 114 can assume that a DL DCI format is not valid when the DLDCI format conveys a DAI value larger than C or UE 114 can assume thatbits of a DAI field for DAI values corresponding to cell indexes largerthan C are set to zero. For example, when UE 114 is configured toreceive PDSCH in c≦16 cells and C_(max)=32, UE 114 can assume that amost significant bit (MSB) of the DAI is set to 0.

Although a DAI design according to the first approach can indicate arelative order of cells where UE 114 is scheduled PDSCH transmissions ina SF, the first approach requires a relatively large number of bits andUE 114 cannot determine whether UE 114 failed to detect DL DCI formatsscheduling PDSCH transmissions in cells with indexes larger than alargest index of a cell that UE 114 detected a DL DCI format schedulinga PDSCH transmission.

In a second approach, to avoid having a large number of bits torepresent a cell-domain DAI, a DAI value V_(DAI) ^(DL-C) can still be arelative counter according to a cell index for a transmitted DL DCIformat but also rely on a sufficiently low probability that UE 114 failsto detect a number of DL DCI formats scheduling respective PDSCHtransmissions in cells indicated by successive values V_(DAI) ^(DL-C).Assuming that UE 114 detects a DL DCI format that schedules a PDSCHtransmission to UE 114 in a cell with index c and includes a DAI fieldwith a first value V_(DAI,1) ^(DL-C), and that UE 114 detects a DL DCIformat that schedules a PDSCH transmission to UE 114 in a cell withindex c+j and includes a DAI field with a second value V_(DAI,2)^(DL-C)=V_(DAI,1) ^(DL-C)+1, and UE 114 does not detect a DL DCI formatscheduling a PDSCH transmission to UE 114 in cells with indexes betweenc and c+j, UE 114 can assume that there is no PDSCH transmission to UE114 in any cell with index between c and c+j. In order to avoid anyadverse effects on operation, a probability of the above assumption tobe incorrect should be much smaller than a probability of incorrectHARQ-ACK detection at eNB 102. For example, assuming a probability of 1e-2 that UE 114 fails to detect a DL DCI format, that this probabilityis independent for different DL DCI formats, and a probability of 1e-4for incorrect HARQ-ACK detection at eNB 102, a probability that UE 114fails to detect 4 DL DCI formats for cells with indexes between c andc+j is 1e-8 (when j≧4) and this probability is sufficiently smaller thanthe probability of 1e-4 for incorrect HARQ-ACK detection at eNB 102.Then, a cell-domain DAI field of 2 bits suffices and mapping can be asin Table 3.

TABLE 3 Value of Cell-Domain Relative Counter DAI DAI Number of DL Cellswith PDSCH MSB, transmission and with PDCCH/EPDCCH LSB V_(DAI) ^(DL-C)indicating DL SPS release 0, 0 1 1 or 5 or 9 or 13 or 17 or 21 or 25 or29 0, 1 2 2 or 6 or 10 or 14 or 18 or 22 or 26 or 30 1, 0 3 3 or 7 or 11or 15 or 19 or 23 or 27 or 31 1, 1 4 0 or 4 or 8 or 12 or 16 or 20 or 24or 28 or 32

For example, when UE 114 detects a DL DCI format having a cell-domainrelative counter DAI field with value V_(DAI) ^(DL-C)=2 and schedulingPDSCH transmission in cell c and UE 114 detects a DL DCI format having acell-domain DAI field value V_(DAI) ^(DL-C)=1 and scheduling PDSCHtransmission in cell c+j, where j>2, UE 114 can determine that UE 114missed detecting two DL DCI formats scheduling respective PDSCHtransmissions in cells with indexes between c and c+j. For example, whenUE 114 detects a DL DCI format having a cell-domain relative counter DAIfield with value V_(DAI) ^(DL-C)=2 and scheduling a PDSCH transmissionin cell c and detects a DL DCI format having a cell-domain relativecounter DAI field with value V_(DAI) ^(DL-C)=3 and scheduling a PDSCHtransmission in cell c+j where j>0, UE 114 can determine that there wasno DL DCI format scheduling a PDSCH transmission to UE 114 in cells withindexes between c and c+j. Therefore, for a cell-domain counter DAIfield with value V_(DAI) ^(DL-C) mapping as in Table 3, UE 114 candetermine whether UE 114 failed to detect up to three DL DCI formatsscheduling respective PDSCH transmissions (or a SPS PDSCH release) inrespective cells with indexes between an index of a first cell and anindex of a second cell that UE 114 detects DL DCI formats schedulingrespective PDSCH transmissions.

Regardless of a size of a cell-domain relative counter DAI field, anadditional mechanism is needed to solve a problem of UE 114 not knowingwhether UE 114 failed to detect DL DCI formats for one or more cellswith larger indexes than a largest index of a cell that UE 114 detects arespective DL DCI format scheduling a PDSCH transmission in a same SF.This problem is similar to one for a TDD system where UE 114 cannotdetermine whether or not UE 114 failed to detect DL DCI formatstransmitted in SFs of a bundling window that occur after a last SFwithin the bundling window where UE 114 detected a DL DCI format.However, unlike a TDD system where eNB 102 cannot predict futurescheduling decisions in order to inform UE 114, eNB 102 knows a numberof DL DCI formats that eNB 102 transmits to UE 114 in a SF and eNB 102can additionally include either a total counter DAI field or a forwardcounter DAI field in the DL DCI format as is subsequently described.

A value V_(DAI,F) ^(DL-C) of a forward counter DAI field in a DL DCIformat can indicate to UE 114 whether or not there are DL DCI formatsscheduling PDSCH transmissions in cells with indexes larger than anindex of a cell that the DL DCI format schedules a PDSCH transmission toUE 114. For example, the forward counter DAI can include 1 bit toindicate whether or not there is at least one more DL DCI formatscheduling a PDSCH transmission in a cell with a larger index, or 2 bitsto indicate whether there are 0, 1, 2, or 3 more DL DCI formatsscheduling respective PDSCH transmissions in respective cells withlarger indexes, and so on. Based on a value of a forward counter DAI ina DL DCI format that UE 114 detects and schedules a PDSCH transmissionfor a cell, UE 114 can determine whether or not UE 114 failed to detectup to three DL DCI formats that schedule PDSCH transmissions in cellswith indexes larger that the index of the cell. A mapping to numericvalues of a forward counter DAI that includes 2 bits can be as in Table4.

TABLE 4 Value of Cell-Domain Forward Counter DAI DAI Number of DL cellswith PDSCH MSB, transmission and with PDCCH/ LSB V_(DAI,F) ^(DL-C)EPDCCH indicating DL SPS release 0, 0 1 1 or 5 or 9 or 13 or 17 or 21 or25 or 29 0, 1 2 2 or 6 or 10 or 14 or 18 or 22 or 26 or 30 1, 0 3 3 or 7or 11 or 15 or 19 or 23 or 27 or 31 1, 1 4 0 or 4 or 8 or 12 or 16 or 20or 24 or 28

FIG. 14 illustrates a functionality of a cell-domain DAI that includes arelative counter DAI and a forward counter DAI according to thisdisclosure.

The eNB 102 configures UE 114 for PDSCH transmissions in ten cells of aFDD system. In a SF, eNB 102 transmits to UE 114 three DL DCI formatsfor Cell#2 1410, Cell#5 1420, and Cell#7 1430. A cell-domain DAI in afirst DL DCI format for Cell#2 includes a relative counter DAI withvalue V_(DAI) ^(DL-C)=1 (binary value ‘00’) and a forward counter DAIwith value V_(DAI,F) ^(DL-C)=2 (binary value ‘01’), a cell-domain DAI ina second DL DCI format for Cell#5 includes a relative counter DAI withvalue V_(DAI) ^(DL-C)=2 (binary value ‘01’) and a forward counter DAIwith value V_(DAI,F) ^(DL-C)=1 (binary value ‘00’), and a cell-domainDAI in a third DL DCI format for Cell#7 includes a relative counter DAIwith value V_(DAI) ^(DL-C)=3 (binary value ‘10’) and a forward counterDAI with value V_(DAI,F) ^(DL-C)=0 (binary value ‘11’). UE 114 fails todetect the DL DCI format for Cell#5 and the DL DCI format for Cell#7.Based on the value of the relative counter DAI and the value of theforward counter DAI in the DL DCI format for Cell#2, UE 114 candetermine that UE 114 failed to detect two DL DCI formats in cells withindexes larger than the index of Cell#2 and UE 114 places NACK/DTXvalues for respective HARQ-ACK information bits after the HARQ-ACKinformation bit for Cell#2.

A value V_(DAI,T) ^(DL-C) of a total counter DAI field in a DL DCIformat can indicate to UE 114 a total number of DL DCI formatsscheduling PDSCH transmissions in respective cells in a SF. For a totalcounter DAI field of 2 bits, a mapping to numeric values V_(DAI,T)^(DL-C) can be as in Table 3 with V_(DAI,T) ^(DL-C) replacing V_(DAI)^(DL-C). Based on a value V_(DAI,T) ^(DL-C) for the total counter DAIand on a value V_(DAI) ^(DL-C) for the relative counter DAI in a DL DCIformat scheduling a PDSCH transmission to UE 114 in a cell, UE 114 candetermine a number of DL DCI formats that UE 114 failed to detect aswell as indexes of cells for the number of DL DCI formats relative tothe index of the cell.

FIG. 15 illustrates a functionality of a cell-domain DAI that includes arelative counter DAI and a total counter DAI according to thisdisclosure.

UE 114 is configured by eNB 102 for PDSCH transmissions in ten cells ofa FDD system. In a SF, eNB 102 transmits to UE 114 three DL DCI formatsfor Cell#2 1510, Cell#5 1520, and Cell#7 1530. A cell-domain DAI in afirst DL DCI format for Cell#2 includes a relative counter DAI withvalue V_(DAI) ^(DL-C)=1 (binary value ‘00’) and a total counter DAI withvalue V_(DAI,T) ^(DL-C)=3 (binary value ‘10’), a cell-domain DAI in asecond DL DCI format for Cell#5 includes a relative counter DAI withvalue V_(DAI) ^(DL-C)=2 (binary value ‘01’) and a total counter DAI withvalue V_(DAI,T) ^(DL-C)=3 (binary value ‘10’), and a cell-domain DAI ina third DL DCI format for Cell#7 includes a relative counter DAI withvalue V_(DAI) ^(DL-C)=3 (binary value ‘10’), and a total counter DAIwith value V_(DAI,T) ^(DL-C)=3 (binary value ‘10’). UE 114 fails todetect the DL DCI format for Cell#2 and the DL DCI format for Cell#7.Based on the value V_(DAI) ^(DL-C)=2 of the relative counter DAI and thevalue V_(DAI,T) ^(DL-C)=3 of the total counter DAI in the DL DCI formatfor Cell#5, UE 114 can determine that UE 114 failed to detect two DL DCIformats, where a first DL DCI format is for a first cell with indexsmaller than the index of Cell#5 and a second DL DCI format is for asecond cell with index larger than the index of Cell#5, and UE 114places NACK/DTX values for the respective HARQ-ACK information bits.

In addition to UE 114 determining a number of cells that UE 114 fails todetect respective DL DCI formats scheduling respective PDSCHtransmissions and an order of a number of cells according to respectiveconfigured indexes, UE 114 needs to determine whether UE 114 needs toconvey one or two HARQ-ACK information bits (both with NACK/DTX value)for each cell from the number of cells according to a PDSCH TM in thecell. When UE 114 applies HARQ-ACK spatial domain bundling, UE 114provides HARQ-ACK feedback only for a number of cells that UE 114determines as having respective PDSCH transmissions (or SPS PDSCHrelease) in a SF. This avoids a dependence of HARQ-ACK information thatUE 114 generates on a respective PDSCH TM and results to UE 114generating one HARQ-ACK information bit for each cell that UE 114identifies as UE 114 having a scheduled PDSCH transmission in a SF. WhenUE 114 does not apply HARQ-ACK spatial domain bundling and UE 114 isconfigured for at least one cell a PDSCH TM that supports more than onedata TB, UE 114 reports two HARQ-ACK information bits for all cells toavoid a dependence of HARQ-ACK information that UE 114 generates on arespective PDSCH TM.

An order of HARQ-ACK information bits in a codeword for transmissionusing a PUCCH format can be according to an order of indexes of cellsthat UE 114 identifies as having a scheduled PDSCH transmission in arespective SF. UE 114 can place a HARQ-ACK information bit in responseto a SPS PDSCH transmission either according to a respective cell indexor at a predetermined location in a HARQ-ACK codeword, such as a firstone or a last one.

FIG. 16 illustrates a generation of HARQ-ACK information bits by a UEbased on a counter DAI field and either on a forward DAI field or on atotal DAI field according to this disclosure.

UE 114 is configured for CA operation and detects one or more DL DCIformats that schedule respective one or more PDSCH transmissions in oneor more respective cells in a SF. A DL DCI format includes a cell-domainDAI field that comprises of a relative counter DAI and either a forwardcounter DAI or a total counter DAI 1610. Based on values of the two DAISfields in the one or more DL DCI formats, UE 114 determines cell indexeswith received and non-received PDSCH transmissions 1620 that correspondto detected or non-detected DL DCI formats. UE 114 generates HARQ-ACKinformation for received and non-received PDSCH transmissions. UE 114can either apply HARQ-ACK spatial domain bundling in case a PDSCH TM isassociated with transmission of two data TBs, or transmit two HARQ-ACKbits per cell when UE 114 is configured with a PDSCH TM associated withtransmission of two data TBs in at least one cell, or transmit oneHARQ-ACK bit per cell when UE 114 is configured with a PDSCH TMassociated with transmission of one data TB in all cells 1630. UE 114arranges the HARQ-ACK information according to cell indexes of receivedand non-received PDSCH transmissions 1640. Finally, UE 114 encodes,modulates, and transmits the HARQ-ACK information using a PUCCH format1650. UE 114 can select the PUCCH format based on a HARQ-ACK payload.

DAI Design for a TDD System

For a TDD system, in addition to a cell dimension, HARQ-ACK codeworddetermination needs to account for a time dimension corresponding to SFsin a bundling window. This is achieved by including in a DL DCI formatboth a cell-domain DAI that UE 114 can use to derive a number of DL DCIformats that eNB 102 transmits to UE 114 in a respective SF of abundling window and a time-domain DAI that UE 114 can use to determinewhether or not UE 114 failed to detect some or all DL DCI formats thateNB 102 transmitted to UE 114 in a previous SF of the bundling window orby including a 2-dimensional DAI spanning both the cell-domain and thetime-domain (cell/time-domain DAI).

When a DL DCI format transmission is in a same SF as an associated PDSCHtransmission (or SPS PDSCH release), there is no difference between aDAI counting DCI format transmissions or PDSCH transmissions. When a DLDCI format transmission is in a first SF and an associated PDSCHtransmission (or SPS PDSCH release) is in a second SF and the second SFcan occur after the first SF, a DAI value needs to count PDSCHtransmissions at least when the first SF and the second SF are notassociated by a predetermined and fixed time difference. For example, aDL DCI format can include a time index of 2 bits that can indicatewhether a SF of an associated PDSCH transmission is 0, 1, 2, or 3 SFsafter a SF of the DL DCI format transmission. Then, for a same cell, aone-to-one mapping between a SF of DCI format transmission and anassociated HARQ-ACK information bit is not ensured while a one-to-onemapping between a SF of PDSCH transmission and an associated HARQ-ACKinformation bit is ensured.

A cell-domain DAI design and functionality can be a relative counteronly in a cell domain as for a FDD system, or a relative counter acrosscells and SFs (cell/time-domain DAI) as subsequently described. Acell/time-domain DAI can be a relative counter DAI mapping first in thecell domain and then in the time domain. A time-domain DAI design andfunctionality can provide a total number of DL DCI formats that eNB 102transmits to UE 114 in a number of SFs of a bundling window assubsequently described.

Unlike a FDD system where UE 114 does not transmit HARQ-ACK informationwhen UE 114 does not detect a DL DCI format in a SF, for a TDD system aresult of UE 114 failing to detect a DL DCI format that eNB 102transmits to UE 114 in a SF of a bundling window after a last SF of thebundling window where UE 114 detects a DL DCI format, is an incorrectdetermination of a HARQ-ACK payload (assuming that UE 114 determines theHARQ-ACK payload based on a number of DL DCI formats the UE 114determines that eNB 102 transmitted in SFs of the bundling window). Forexample, in a last SF of a bundling window with DL DCI formattransmissions to UE 114, eNB 102 can transmit only one DL DCI format toUE 114 and when UE 114 fails to detect the one DL DCI format, UE 114 isnot able to accurately determine a HARQ-ACK payload over the bundlingwindow. In this example, the problem can be addressed by a receiverimplementation of eNB 102 to determine whether or not UE 114 transmits afirst HARQ-ACK payload or a second HARQ-ACK payload. The first HARQ-ACKpayload can be one corresponding to UE 114 having a correctdetermination of transmitted DL DCI formats in a bundling window and thesecond HARQ-ACK payload can be one corresponding to UE 114 failing todetermine transmitted DL DCI formats in a last SF within a bundlingwindow where eNB 102 transmits DL DCI formats to UE 114.

In a first approach, when UE 114 transmits a first HARQ-ACK payloadusing a first PUCCH format or a first PUCCH resource and UE 114transmits a second HARQ-ACK payload using a second PUCCH format or asecond PUCCH resource, eNB 102 can determine the PUCCH format or thePUCCH resource that UE 114 uses to transmit the HARQ-ACK payload bydetermining a discontinuous transmission (DTX) for the other PUCCHformat or the other PUCCH resource. For example, DTX can be determinedwhen a received signal power, such as a RS power, is below a threshold.

In a second approach, for example when UE 114 can use a same PUCCHformat and a same PUCCH to transmit different HARQ-ACK payloads, eNB 102can perform decoding operations according to a first HARQ-ACK payloadand according to a second HARQ-ACK payload and select a hypothesisresulting to a larger normalized decoding metric such as a largerlikelihood metric for a decided codeword according to the first or thesecond HARQ-ACK payload.

In a third approach, for example when UE 114 can use a same PUCCH formatand a same PUCCH to transmit different HARQ-ACK payloads, UE 114 caninclude a CRC in an encoding of a HARQ-ACK information codeword and eNB102 can detect a HARQ-ACK codeword according to a set of differentpossible HARQ-ACK payloads and determine a HARQ-ACK codeword based on asuccessful CRC check (CRC checksum is zero).

In a fourth approach, when UE 114 uses a same PUCCH format and a samePUCCH resource to transmit a first HARQ-ACK payload and a secondHARQ-ACK payload, UE 114 can be configured to use different attributesof an associated DMRS according to a last SF within a bundling windowwhere UE 114 detects a DL DCI format. For example, UE 114 can use afirst CS/OCC for a DMRS transmission when UE 114 detects a last DL DCIformat in a first SF of a bundling window, a second CS/OCC for a DMRStransmission when UE 114 detects a last DL DCI format in a second SF ofa bundling window, and so on. When a number of SFs in a bundling windowM_(W) is larger than a number of DMRS CS/OCCs M_(CS/OCC), UE 114 can usea first CS/OCC value for SF M_(CS/OCC)+1, and so on.

FIG. 17 illustrates a procedure for a UE to transmit and for an eNB todetect an HARQ-ACK information payload according to this disclosure.

UE 114 encodes and transmits a HARQ-ACK payload in a PUCCH using a PUCCHformat in a PUCCH resource 1710. The eNB 102 considers at least twohypotheses for a received HARQ-ACK payload size 1720. Each of at leasttwo hypotheses can be associated with a different PUCCH format, or withdifferent resources, or with a same PUCCH format and a same resource.The eNB 102 determines a metric for each of the at least two hypotheses1730. For example, a metric can be a received power for each of thedifferent PUCCH formats or resources, or a likelihood metric for adecoded HARQ-ACK codeword for each of the at least two hypotheses, or aCRC check result for a decoded HARQ-ACK codeword for each of the atleast two hypotheses, or a DMRS received power for each of the at leasttwo hypotheses assuming that each of the at least two hypothesescorresponds to a different CS/OCC for the DMRS. The eNB 102 decides onone of the at least two hypotheses based at least on a value of therespective metrics 1740. The eNB 102 can further condition a decisiondepending on a probability for a respective metric. For example eNB 102can assign a larger weight to a metric corresponding to UE 114 detectingat least one DL DCI format from one or more DL DCI formats that eNB 102transmits to UE 114 in a last SF within a bundling window.

An alternative to using a cell-specific functionality for a time-domainDAI is to change the functionality of the time-domain DAI to cell-common(time-domain total counter DAT). When UE 114 detects a DL DCI formatscheduling a PDSCH transmission on a cell in a SF within a bundlingwindow, a cell-domain DAI value V_(DAI) ^(DL-C) can provide a totalnumber of DL DCI formats transmitted to UE 114 in the SF of the bundlingwindow while a time-domain DAI value V_(DAI,T) ^(DL-T) can provide acount of DL DCI formats transmitted in previous SFs of the bundlingwindow, when any, and in the SF. In this manner, UE 114 can use a valueV_(DAI,T) ^(DL-T) of a time-domain total counter DAI field in a DL DCIformat to determine a number of DL DCI formats that UE 114 failed todetect in respective SFs of a bundling window that occur prior to or atthe SF where UE 114 detects the DL DCI format that includes thetime-domain total counter DAI field with value V_(DAI,T) ^(DL-T).

A time-domain total counter DAI value V_(DAI,T) ^(DL-T) acts as acounter for all DL DCI formats transmitted to UE 114 in all SFs (acrossall cells) up to a SF where eNB 102 transmits the DL DCI format thatincludes the time-domain total counter DAI value V_(DAI,T) ^(DL-T). As aconsequence, unlike a FDD system, a cell-domain DAI for a TDD systemneed only include a relative counter V_(DAI) ^(DL-C) of a DL DCI formatfor a cell according to a cell index. A cell-common functionality of atime-domain total counter DAI value V_(DAI,T) ^(DL-T) does not precludeUE 114 from incorrectly determining a HARQ-ACK payload for transmissionin a PUCCH when UE 114 fails to detect any DL DCI format that eNB 102transmits to UE 114 in a last SF within a bundling window (and thereforemeans such as ones described with respect to FIG. 17 can be additionallyneeded by eNB 102 to correctly detect a HARQ-ACK codeword transmitted byUE 114). However, a cell-common functionality of a time-domain totalcounter DAI can result to a correct HARQ-ACK payload determination andarrangement of HARQ-ACK information bits in a codeword (HARQ-ACKcodebook determination) for HARQ-ACK transmission in a PUSCH where a DAIfield in a DL DCI format scheduling a PUSCH transmission (UL DAI) canserve as time-domain total counter DAI for a last SF in a bundlingwindow where eNB 102 transmits to UE 114 DL DCI formats scheduling PDSCHtransmissions.

FIG. 18 illustrates a combined functionality of a relative counter DAIand of a total counter DAI according to this disclosure.

The eNB 102 configures UE 114 ten DL cells for PDSCH transmissions in aTDD system where a bundling window size includes four SFs. In a firstSF, SF#0 1810, eNB 102 transmits to UE 114 three DL DCI formatsscheduling PDSCH transmissions in Cell#2, Cell#5, and Cell#7,respectively. A cell-domain counter DAI in a DL DCI format for Cell#2has a value V_(DAI) ^(DL-C) of ‘00’ for a counter of the DL DCI format,a cell-domain counter DAI in a DL DCI format for Cell#5 has a valueV_(DAI) ^(DL-C) of ‘01’ for a counter of the DL DCI format, and acell-domain counter DAI in a DL DCI format for Cell#7 has a valueV_(DAI) ^(DL-C) of ‘10’ for a counter of the DL DCI format. In SF#0, atime-domain total counter DAI in each of the three DL DCI formats has avalue V_(DAI,T) ^(DL-T) of ‘10’ (corresponds to a numeric value of 3).

In a second SF, SF#1 1820, eNB 102 transmits to UE 114 three DL DCIformats scheduling PDSCH transmissions in Cell#3, Cell#6, and Cell#7. Acell-domain counter DAI in a DL DCI format for Cell#3 has a valueV_(DAI) ^(DL-C) of ‘00’ for a counter of the DL DCI format, acell-domain counter DAI in a DL DCI format for Cell#6 has a valueV_(DAI) ^(DL-C) of ‘01’ for a counter of the DL DCI format, and acell-domain counter DAI in a DL DCI format for Cell#7 has a valueV_(DAI) ^(DL-C) of ‘10’ for a counter of the DL DCI format. In SF#1, atime-domain total counter DAI in each of the three DL DCI formats has avalue V_(DAI,T) ^(DL-T) of ‘01’ (equivalent to a numeric value of 6).

In a third SF, SF#2 1830, eNB 102 transmits to UE 114 two DL DCI formatsscheduling PDSCH transmissions in Cell#5 and Cell#7 and UE 114 fails todetect both DL DCI formats. A cell-domain counter DAI in a DL DCI formatfor Cell#5 has a value V_(DAI) ^(DL-C) of ‘00’ for a counter of the DLDCI format and a cell-domain counter DAI in a DL DCI format for Cell#7has a value V_(DAI) ^(DL-C) of ‘01’ for a counter of the DCI format. InSF#2, a time-domain total counter DAI in each of the two DL DCI formatshas a value V_(DAI,T) ^(DL-T) of ‘11’ (corresponds to a numeric value of8).

In a fourth SF, SF#3 1840, eNB 102 transmits to UE 114 three DL DCIformats scheduling PDSCH transmissions in Cell#3, Cell#6, and Cell#7. Acell-domain counter DAI in a DL DCI format for Cell#3 has a valueV_(DAI) ^(DL-C) of ‘00’ for a counter of the DL DCI format, acell-domain counter DAI in a DL DCI format for Cell#6 has a valueV_(DAI) ^(DL-C) of ‘01’ for a counter of the DL DCI format, and acell-domain counter DAI in a DL DCI format for Cell#7 has a valueV_(DAI) ^(DL-C) ‘10’ for a counter of the DL DCI format. In SF#3, atime-domain total counter DAI in each of the three DL DCI formats has avalue V_(DAI,T) ^(DL-T) of ‘10’ (corresponds to a numeric value of 11).UE 114 knows that the time-domain total counter DAI value V_(DAI)^(DL-CT) is a numeric 6 in SF#1 and a numeric 11 in SF#3, determines 3DL DCI formats in SF#3, and therefore UE 114 knows that UE 114 failed todetect 2 DL DCI formats in SF#2.

Instead of a time-domain total DAI being a cell-common total counterDAI, a cell/time-domain relative counter DAI can be used. Acell/time-domain relative counter DAI field can be same as an existingDAI field in a DL DCI format for a TDD system but with a differentinterpretation. For example, for CA operation with up to five DL cellsin a TDD system, DL DCI formats include a DAI field of 2 bits that iscell-specific and functions as a relative counter of DL DCI formats inSFs of a bundling window for a cell (see also REF 2 and REF 3). For CAoperation with more than 5 DL cells in a TDD system, a DAI field in a DLDCI format scheduling a PDSCH transmission in a SF on a cell provides acounter V_(DAI) ^(DL-CT) of DL DCI formats, up to the SF and the cell,first across cells starting from a cell with a smallest index (Cell#0)and then across SFs in a bundling window starting from a SF with asmallest index (SF#0). A configuration for a use of a DAI field in a DLDCI format can be implicit, such as for example when UE 114 isconfigured with a number of cells that is larger than a predeterminednumber, such as 5, or explicit such as by 1-bit indicating either acell-specific use of a counter DAI field across SFs of a bundling window(as in REF 2 and REF 3) or a 2-dimensional use of the counter DAI fieldfirst across cells and then across SFs up to a SF and a cellcorresponding to the DL DCI format. For a number of C configured cellsand a bundling window size of M_(W) SFs, a joint cell/time-domainrelative counter DAI field can include 2 bits and a mapping of V_(DAI)^(DL-CT) can be as a mapping of V_(DAI) ^(UL-CT) in Table 5 (samemapping applies for values V_(DAI,T) ^(DL-T) of a time-domain totalcounter DAI field of 2 bits).

TABLE 5 Cell/Time-Domain Relative Counter DAI Values in a DL DCI FormatNumber of DL cells with PDSCH DAI transmissions and with MSB,PDCCH/EPDCCH LSB V_(DAI) ^(DL-CT) indicating DL SPS release. 0, 0 1 1 or5 or 9 or 13 or 17 or 21 or 25 or 29 . . . or M_(W) · C − 3 0, 1 2 2 or6 or 10 or 14 or 18 or 22 or 26 or 30 . . . or M_(W) · C − 2 1, 0 3 3 or7 or 11 or 15 or 19 or 23 or 27 or 31 . . . or M_(W) · C − 1 1, 1 4 0 or4 or 8 or 12 or 16 or 20 or 24 or 28 or 32 . . . or M_(W) · C

For brevity, in the following, a cell/time-domain relative counter DAIis referred to as counter DAI and a time-domain total DAI is referred toas total DAI.

FIG. 19 illustrates a determination and arrangement for a HARQ-ACKinformation payload using a counter DAI for a TDD system according tothis disclosure.

UE 114 is configured by eNB 102 for PDSCH transmissions in ten cells ofa TDD system where a bundling window size includes four SFs. In a firstSF, SF#0 1910, eNB 102 transmits to UE 114 three DL DCI formatsscheduling respective PDSCH transmissions in Cell#2, Cell#5, and Cell#7.A counter DAI in a respective DL DCI format has a value V_(DAI)^(DL-CT)=1 for Cell#2, a value V_(DAI) ^(DL-CT)=2 for Cell#5, and avalue V_(DAI) ^(DL-CT)=3 for Cell#7. In a second SF, SF#1 1920, eNB 102transmits to UE 114 three DL DCI formats scheduling respective PDSCHtransmissions in Cell#3, Cell#6, and Cell#7. A counter DAI in arespective DL DCI format has a value V_(DAI) ^(DL-CT)=4 for Cell#3, avalue V_(DAI) ^(DL-CT)=5 for Cell#6, and a value V_(DAI) ^(DL-CT)=6 forCell#7. In a third SF, SF#2 1930, eNB 102 transmits to UE 114 two DL DCIformats scheduling respective PDSCH transmissions in Cell#5 and Cell#7.A counter DAI in a respective DL DCI format has a value V_(DAI)^(DL-CT)=7 for Cell#5 and a value V_(DAI) ^(DL-CT)=8 for Cell#7. In afourth SF, SF#3 1940, eNB 102 transmits to UE 114 two DL DCI formatsscheduling respective PDSCH transmissions in Cell#3 and Cell#7. Acounter DAI in a respective DL DCI format has a value V_(DAI) ^(DL-CT)=9for Cell#3 and a value V_(DAI) ^(DL-CT)=10 for Cell#7.

In SF#0 1910, UE 114 detects the first and third DL DCI formats andfails to detect the second DL DCI format. From the values V_(DAI)^(DL-CT)=1 and V_(DAI) ^(DL-CT)=3 of the counter DAI in the two detectedDL DCI formats in SF#0, UE 114 determines that UE 114 failed to detect aDL DCI format for a cell with index larger than 2 and smaller than 7.Therefore, UE 114 can determine and arrange the HARQ-ACK informationbits as {x, NACK/DTX, x}, where ‘x’ represents either an ACK or aNACK/DTX, in response to receptions or absence of receptions of PDSCHtransmissions scheduled by DL DCI formats transmitted in SF#0. In SF#11920, UE 114 detects the first and second DL DCI formats and fails todetect the third DL DCI format. From the values V_(DAI) ^(DL-CT)=4 andV_(DAI) ^(DL-CT)=5 of the counter DAI in the two detected DL DCI formatsin SF#1, UE 114 determines that UE 114 did not fail to detect any otherDL DCI format in SF#0. For SF#0 and SF#1, the UE can generate HARQ-ACKinformation bits as {x, NACK/DTX, x, x, x}. In SF#2 1930, UE 114 detectsboth the first and second DL DCI formats. From the value V_(DAI)^(DL-CT)=7 of the counter DAI in the detected DL DCI format for Cell#5in SF#2, UE 114 determines that UE 114 failed to detect a DL DCI formatin SF#1 for a cell with larger index than Cell#6. From the value V_(DAI)^(DL-CT)=8 of the counter DAI in the detected DL DCI format for Cell#7in SF#2, UE 114 determines that UE 114 did not fail to detect a DL DCIformat in SF#2 for a cell with smaller index than Cell#7. For SF#0,SF#1, and SF#2, UE 114 can generate HARQ-ACK information bits as {x,NACK/DTX, x, x, x, NACK/DTX, x, x}. In SF#3 1940, UE 114 fails to detectboth the first and second DL DCI formats and UE 114 cannot determinethis error event.

The functionalities of a counter DAI (as described in FIG. 19) and of atotal counter DAI (as described in FIG. 18) can be combined. A DL DCIformat transmitted in a SF for PDSCH transmission in a cell can includea counter DAI providing a counter of DL DCI formats across cells and SFsup to the SF and the cell, and a total counter DAI providing a totalnumber of DL DCI formats across cells and SFs up to the SF. Relative tothe operation in FIG. 18, a (cell/time-domain) counter DAI replaces acell-domain relative counter DAI. A resulting functionality ispractically equivalent.

FIG. 20 illustrates a determination and arrangement for a HARQ-ACKinformation payload using a value of a counter DAI and a value of atotal DAI for a TDD system according to this disclosure.

The eNB 102 configures UE 114 for PDSCH transmissions in ten cells of aTDD system where a bundling window size includes four SFs. In a firstSF, SF#0 2010, eNB 102 transmits to UE 114 three DL DCI formatsscheduling respective PDSCH transmissions in Cell#2, Cell#5, and Cell#7.A counter DAI in a respective DL DCI format has a value V_(DAI)^(DL-CT)=1 for Cell#2, a value V_(DAI) ^(DL-CT)=2 for Cell#5, and avalue V_(DAI) ^(DL-CT)=3 for Cell#7 and a total counter DAI in each ofthe three DL DCI formats has a value V_(DAI,T) ^(DL-T)=3. In a secondSF, SF#1 2020, eNB 102 transmits to UE 114 three DL DCI formatsscheduling respective PDSCH transmissions in Cell#3, Cell#6, and Cell#7.A counter DAI in a respective DL DCI format has a value V_(DAI)^(DL-CT)=4 for Cell#3, a value V_(DAI) ^(DL-CT)=5 for Cell#6, and avalue V_(DAI) ^(DL-CT)=6 for Cell#7 and a total counter DAI in each ofthe three DL DCI formats has a value V_(DAI,T) ^(DL-T)=6. In a third SF,SF#2 2030, eNB 102 transmits to UE 114 two DL DCI formats schedulingrespective PDSCH transmissions in Cell#5, and Cell#7. A counter DAI in arespective DL DCI format has a value V_(DAI) ^(DL-CT)=7 for Cell#5 and avalue V_(DAI) ^(DL-CT)=8 for Cell#7 and a total counter DAI in each ofthe two DL DCI formats has a value V_(DAI,T) ^(DL-T)=8. In a fourth SF,SF#3 2040, eNB 102 transmits to UE 114 two DL DCI formats schedulingrespective PDSCH transmissions in Cell#3 and Cell#7. A counter DAI in arespective DL DCI format has a value V_(DAI) ^(DL-CT)=9 for Cell#3 and avalue V_(DAI) ^(DL-CT)=10 for Cell#7 and a total counter DAI in each ofthe two DL DCI formats has a value V_(DAI,T) ^(DL-CT)=10. For SF#0,SF#1, and SF#2, a determination and arrangement of HARQ-ACK informationusing a value of a counter DAI can be as in FIG. 19. A usefulness of thetotal counter DAI V_(DAI,T) ^(DL-T) appears in SF#3 where UE 114 detectsa DL DCI format scheduling a PDSCH in Cell#3 but fails to detect a DLDCI format scheduling a PDSCH in Cell#7. Without the inclusion of thetotal counter DAI V_(DAI,T) ^(DL-T) in DL DCI formats, UE 114 is unableto determine that UE 114 failed to detect a DL DCI format scheduling aPDSCH in a cell with index larger than the index of Cell#3. With theinclusion of the total counter DAI V_(DAI,T) ^(DL-T) in DL DCI formats,based on the V_(DAI,T) ^(DL-T) value in the DL DCI format schedulingPDSCH in Cell#3 (in SF#3) that UE 114 detects, UE 114 can determine thatUE 114 failed to detect a DL DCI format scheduling a PDSCH in a cellwith index larger than the index of Cell#3.

DL DCI Format Transmission in a CSS

A DL DCI format, such as DCI format 1A, that eNB 102 transmits in a CSSof a primary cell and schedules a PDSCH transmission on a primary celldoes not include new fields for a (cell/time-domain) counter DAI and fora (time-domain) total counter DAI for a FDD system or for a totalcounter DAI for a TDD system. This is because a size of DCI format 1Awhen transmitted in a CSS needs to be same as a size of a DCI format3/3A that is transmitted in the CSS and needs to be decoded by a groupof UEs where at least some UEs in the group of UEs can be unaware of achange in the size of DCI format 1A in case a counter DAI or a total DAIare included in DCI format 1A.

For a FDD system, when UE 114 detects a DCI format 1A that istransmitted in a CSS and schedules a PDSCH on a primary cell, and UE 114also detects at least one other DL DCI format that is transmitted in aUSS and schedules a PDSCH reception on a secondary cell, a value for acounter DAI and a value for a total DAI in the at least one other DL DCIformat counts the transmission of DCI format 1A and UE 114 placesHARQ-ACK information for DCI format 1A in a first position of anassociated HARQ-ACK codeword.

For a TDD system, when UE 114 detects a DCI format 1A in a CSS in a SFof a bundling window that schedules a PDSCH on a primary cell, and UE114 also detects at least one other DL DCI format in a USS in the SF orin a later SF of the bundling window, a value for a counter DAI and avalue for a total DAI in the at least one other DL DCI format includescounting of DCI format 1A. UE 114 places HARQ-ACK information for DCIformat 1A in a first position for HARQ-ACK information that UE 114determines for the SF. The first position for HARQ-ACK information thatUE 114 determines for the SF is the first position in an associatedHARQ-ACK codeword only when the SF is the first SF in the bundlingwindow.

FIG. 21 illustrates a determination and arrangement for a HARQ-ACKinformation payload when a DL DCI format is transmitted in a CSS for aTDD system according to this disclosure.

The eNB 102 configures UE 114 for PDSCH transmissions in ten cells of aTDD system where a bundling window size includes four SFs. In a firstSF, SF#0 2010, eNB 102 transmits to UE 114 three DL DCI formatsscheduling respective PDSCH transmissions in Cell#2, Cell#5, and Cell#7.A counter DAI in a respective DL DCI format has a value V_(DAI)^(DL-CT)=1 for Cell#2, a value V_(DAI) ^(DL-CT)=2 for Cell#5, and avalue V_(DAI) ^(DL-CT)=3 for Cell#7 and a total DAI in each of the threeDL DCI formats has a value V_(DAI,T) ^(DL-T)=3. In a second SF, SF#12020, eNB 102 transmits to UE 114 three DL DCI formats schedulingrespective PDSCH transmissions in Cell#0, Cell#6, and Cell#7 and the DLDCI format that schedules PDSCH transmission in Cell#0 is transmitted ina CSS and does not include a total DAI. A counter DAI in a respective DLDCI format has a value V_(DAI) ^(DL-CT)=4 for Cell#0, a value V_(DAI)^(DL-CT)=5 for Cell#6, and a value V_(DAI) ^(DL-CT)=6 for Cell#7 and atotal DAI in the second and third DL DCI formats of the three DL DCIformats has a value V_(DAI,T) ^(DL-T)==6. In a third SF, SF#2 2030, eNB102 transmits to UE 114 two DL DCI formats scheduling respective PDSCHtransmissions in Cell#5, and Cell#7. A counter DAI in a respective DLDCI format has a value V_(DAI) ^(DL-CT)=7 for Cell#5 and a value V_(DAI)^(DL-CT)=8 for Cell#7 and a total DAI in each of the two DL DCI formatshas a value V_(DAI,T) ^(DL-T)=8. In a fourth SF, SF#3 2040, eNB 102transmits to UE 114 two DL DCI formats scheduling respective PDSCHtransmissions in Cell#0 and Cell#7 and the DL DCI format that schedulesPDSCH transmission in Cell#0 is transmitted in a CSS and does notinclude a total DAI. A counter DAI in a respective DL DCI format has avalue V_(DAI) ^(DL-CT)=9 for Cell#0 and a value V_(DAI) ^(DL-CT)=10 forCell#7 and a counter DAI in the second of the two DL DCI formats has avalue V_(DAI) ^(DL-T)=10. HARQ-ACK information for the DL DCI formattransmitted in the CSS in SF#1 2120 is placed fourth in a HARQ-ACKcodeword as a respective counter DAI value is V_(DAI) ^(DL-CT)=4 and atotal DAI value in SF#0 is V_(DAI,T) ^(DL-T)=3. HARQ-ACK information forthe DL DCI format transmitted in the CSS in SF#3 2140 is placed ninth inthe HARQ-ACK codeword as a respective counter DAI value is V_(DAI)^(DL-CT)=9 and a total DAI value in SF#2 is V_(DAI,T) ^(DL-T)=8.

Resolution of Error Cases

It is also possible that UE 114 fails to detect any transmitted DL DCIformat in SFs after a last SF where UE 114 detects a DL DCI format, forexample as in FIG. 19. Then, regardless of DAI types in a DL DCI format,UE 114 cannot determine a correct HARQ-ACK information payload. The eNB102 can resolve this ambiguity using one of the four previouslydescribed approaches. For example, according to the third approach andfor a TDD system and for the exemplary case in FIG. 19 or FIG. 20 orFIG. 21, eNB 102 can attempt detection and perform a CRC check(determine whether or not a CRC checksum is zero) for each of the fourfollowing HARQ-ACK information payload values corresponding to thefollowing

-   (a) UE 114 detects at least one DL DCI format in SF#0 and does not    detect any DL DCI format in SF#1 and SF#2 and SF#3 (UE 114    determines a first HARQ-ACK information payload, can be considered    as the least likely scenario)-   (b) UE 114 detects at least one DL DCI format in SF#1 and does not    detect any DL DCI format in SF#2 and SF#3 (UE 114 determines a    second HARQ-ACK information payload, can be considered as the second    least likely scenario)-   (c) UE 114 detects at least one DL DCI format in SF#2 and does not    detect any DL DCI format in SF#3 (UE 114 determines a third HARQ-ACK    information payload, can be considered as the second most likely    scenario)-   (d) UE detects at least one DL DCI format in SF#3 (UE 114 determines    a fourth HARQ-ACK information payload, can be considered as the most    likely scenario)

When UE 114 transmits HARQ-ACK information using a PUCCH format thatdepends on a HARQ-ACK information payload, for example as described inFIG. 13, eNB 102 can attempt detection of multiple PUCCH formats. Forexample, when UE 114 determines a first HARQ-ACK information payload, UE114 can use a PUCCH Format 3 while when UE 114 determines a secondHARQ-ACK information payload, UE 114 can use a PUCCH Format 4 having aPUSCH-based structure. The eNB 102 can determine whether UE 114transmits a PUCCH Format 3 by detecting a received energy in a resourcethat UE 114 can use to transmit the PUCCH Format 3 (DTX detection). TheeNB 102 can determine whether UE 114 transmits a PUCCH Format 4 bydetecting a received energy in a resource that UE 114 can use totransmit the PUCCH Format 4 or by relying on a check of a CRC that isincluded with the HARQ-ACK information payload in an encoded codewordwhen UE 114 uses PUCCH Format 4.

FIG. 22 illustrates a procedure for eNB 102 to detect an HARQ-ACKcodeword in a PUCCH using a CRC check or, in case of multiple possiblePUCCH formats, a DTX detection for some of the PUCCH formats accordingto this disclosure.

The eNB 102 first decodes a HARQ-ACK codeword according to a HARQ-ACKinformation payload, a PUCCH format, and a PUCCH resource that eNB 102expects UE 114 to use in response to transmissions of DL DCI formatsfrom eNB 102 to UE 114 in one or more SFs 2210. When a check for a CRC,when included in an encoded HARQ-ACK codeword, is positive (CRC checksumis zero) 2220, eNB 102 considers a HARQ-ACK information obtained from adecoded HARQ-ACK codeword as valid 2230. It is also possible that anencoded HARQ-ACK codeword does not include a CRC, such as when UE 114uses a PUCCH format 3, and in such case eNB 102 can determine whether UE114 transmits a respective PUCCH based on energy detection at arespective PUCCH resource (absence of DTX detection). When the CRC checkis not positive (CRC checksum is not zero) or when eNB 102 detects DTX,eNB 102 proceeds to decode a HARQ-ACK codeword according to a nextsmaller HARQ-ACK information payload, relative to an expected HARQ-ACKinformation payload based on the transmitted DL DCI formats, and arespective PUCCH format and a PUCCH resource 2240 and repeats step 2220.For example, for transmissions of DL DCI formats as in FIG. 19 or FIG.20, an expected HARQ-ACK payload corresponds to one for DL DCI formatstransmitted in four SFs (ten DL DCI formats) while a next smallerHARQ-ACK information payload corresponds to DL DCI formats transmittedin the first three SFs (eight DL DCI formats). When the CRC check is notpositive, eNB 102 proceeds to decode a HARQ-ACK codeword first accordingto a HARQ-ACK information payload that corresponds to DL DCI formatstransmitted in the first two SFs (six DL DCI formats) and then, when theCRC check is also not positive, according to a HARQ-ACK informationpayload that corresponds to DL DCI formats transmitted in the first SF(three DL DCI formats). The above steps for the eNB 102 decodingattempts can also be performed in parallel or with a different order.

Determination of Payload and Arrangement of Information Bits in aCodeword for HARQ-ACK Transmission in a PUSCH

For a FDD system, when a cell-domain DAI in a DL DCI format scheduling aPDSCH transmission to UE 114 in a cell includes both a counter oftransmitted DL DCI formats (or PDSCH transmissions) and either a forwardcounter of DL DCI format or a total number of DL DCI formats (or PDSCHtransmissions), UE 114 can determine a number of DL DCI formats that eNB102 transmits to UE 114 in a SF to schedule PDSCH transmissions(including SPS PDSCH release) in respective cells. UE 114 can alsodetermine an order of respective cell indexes to arrange respectiveHARQ-ACK information in a codeword according to an ascending order ofcell indexes. Then, assuming that either spatial-domain bundling appliesor reported HARQ-ACK information for a cell includes two HARQ-ACKinformation bits regardless of a PDSCH TM when a PDSCH TM for at leastone cell supports two data TBs (otherwise, by default, reported HARQ-ACKinformation for all cells includes 1 HARQ-ACK bit), UE 114 can determinean HARQ-ACK payload to transmit in a PUSCH in a same manner as in aPUCCH and an UL DAI in an UL DCI format scheduling a PUSCH transmissionfrom UE 114 is not needed. An error case happens only when UE 114 failsto detect all DL DCI that eNB 102 transmits to UE 114 in a last SFwithin a bundling window.

For a TDD system, when a DL DCI format includes both a cell-domain DAIand a time-domain DAI, where for example the cell-domain DAI can be acounter of DL DCI formats (or PDSCH transmissions) in a SF according toan ascending order of a respective cell index and the time-domain DAIcan be a total counter of DL DCI formats (or PDSCH transmissions) inpast SF and a present SF of a same bundling window, or when a singlecounter DAI operates in the joint cell/time-domain (cell-first mappingof DAI values), UE 114 can determine a number of DL DCI formats that eNB102 transmits to UE 114 in a bundling window to schedule PDSCHtransmissions in respective cells and SFs. UE 114 can also determine anorder of respective cell indexes and SFs to arrange respective HARQ-ACKinformation in a codeword according to an ascending order of cellindexes per SF and then according to an ascending order of SFs. Then, UE114 can determine an HARQ-ACK payload to transmit in a PUSCH. An errorcase occurs when UE 114 fails to detect all transmitted DL DCI formats(or PDSCH transmissions) that eNB 102 transmits to UE 114 in a last SFwithin bundling window.

To avoid error cases where UE 114 can have a different understandingthan eNB 102 of a number or an order of DL DCI formats transmitted fromeNB 102 to UE 114, a DAI field can be included in an UL DCI formatscheduling a PUSCH transmission from UE 114. The DAI field can indicatea total number of transmitted DL DCI formats that schedule PDSCHtransmissions to UE 114 (or can indicate a total number of PDSCHtransmissions), either in a SF for a FDD system or in a bundling windowfor a TDD system. Otherwise, when error cases are practicallyimmaterial, a DAI field does not need to be included or used in an ULDCI format scheduling a PUSCH transmission and UE 114 determines aHARQ-ACK codeword in a same manner as for transmission in a PUCCH.

For a FDD system, when UE 114 adjusts a PUSCH transmission based on adetected UL DCI format, UE 114 can obtain a DAI value, V_(DAI) ^(UL-C).UE 114 can use V_(DAI) ^(UL-C) to determine an HARQ-ACK informationpayload, O_(HARQ-ACK), to multiplex in the PUSCH.

When UE 114 is configured with a maximum of C cells, a cell-domain totalcounter DAI field, or simply DAI field, in an UL DCI can include, forexample, 2 bits having a mapping to respective numeric values V_(DAI)^(UL-C) as in Table 6. Although each combination of the two bits can mapto multiple numeric values, an error occurs only when UE 114 fails todetect three successive (based on a cell index) DL DCI formats and, fortypical block error rate (BLER) values of 1 e-2 that UE 114 fails todetect a DCI format, this is an immaterial event.

TABLE 6 Cell-Domain Total DAI Values in an UL DCI Format for a FDDSystem DAI Number of DL Cells with PDSCH MSB, transmissions and withPDCCH/EPDCCH LSB V_(DAI) ^(UL-C) indicating DL SPS release 0, 0 1 1 or 5or 9 or 13 or 17 or 21 or 25 or 29 . . . or C − 3 0, 1 2 2 or 6 or 10 or14 or 18 or 22 or 26 or 30 . . . or C − 2 1, 0 3 3 or 7 or 11 or 15 or19 or 23 or 27 or 31 . . . or C − 1 1, 1 4 0 or 4 or 8 or 12 or 16 or 20or 24 or 28 or 32 . . . or C

It is O_(HARQ-ACK)=V_(DAI) ^(UL-C) (for 1 bit HARQ-ACK per DL DCIformat; otherwise, it is O_(HARQ-ACK)=2·V_(DAI) ^(UL-C)) unless V_(DAI)^(UL-C)=4 and U_(DAI) ^(Cell)+N_(SPS)=0 (UE 114 does not detect a DL DCIformat scheduling a PDSCH transmission and does not have a SPS PDSCHtransmission in a SF) and then UE 114 does not transmit HARQ-ACK in aPUSCH. A spatially bundled HARQ-ACK information bit with indexo_(HARQ-ACK), 0≦o_(HARQ-ACK) is associated with a PDSCH transmissionscheduled by a DL DCI format with cell-domain DAI value o_(HARQ-ACK)+1where UE 114 sets a value of the HARQ-ACK information bit with indexo_(HARQ-ACK) to a NACK/DTX value when UE 114 does not detect a DL DCIformat scheduling a PDSCH transmission and having a counter DAI value ofV_(DAI) ^(DL-C)=o_(HARQ-ACK)+1 (UE 114 determines existence of the DLDCI format from a counter DAI or from a total DAI in a next DL DCIformat or from the DAI in the UL DCI format). When N_(SPS)>0, a HARQ-ACKinformation bit associated with a SPS PDSCH transmission is assignedindex O_(HARQ-ACK)−1 (placed last in a HARQ-ACK codeword).

FIG. 23 illustrates a determination and arrangement for a HARQ-ACKinformation payload transmission in a PUSCH transmission using arelative counter DAI value in a DL DCI format scheduling a PDSCHtransmission and a total DAI value in an UL DCI format scheduling aPUSCH transmission for a FDD system according to this disclosure.

UE 114 is configured by eNB 102 for PDSCH transmissions in ten cells ofa FDD system. In a first case, UE 114 detects a DL DCI format thatschedules a PDSCH transmission in Cell#2 and includes a cell-domaincounter DAI field having a value V_(DAI) ^(DL-C)=1 2310. UE 114 fails todetect DL DCI formats scheduling PDSCH transmissions for Cell#5 2312 andCell#7 2314. UE 114 also detects an UL DCI format scheduling a PUSCHtransmission in a SF where eNB 102 expects UE 114 to transmit HARQ-ACKin response to PDSCH transmissions in Cell#2, Cell#5, and Cell#7 wherethe UL DCI format includes a cell-domain total DAI field having a valueV_(DAI) ^(UL-C)=3 2320. Based on the value of V_(DAI) ^(DL-C)=1 andV_(DAI) ^(UL-C)=3, UE 114 determines that UE 114 failed to detect 2 DLDCI formats scheduling PDSCH transmissions in cells with index largerthan 2 (the index for Cell#2) and UE 114 generates a HARQ-ACK codewordof {x, NACK/DTX, NACK/DTX} 2330 for transmission in the PUSCH where ‘x’is either ACK or NACK/DTX depending on a correct or incorrect detectionof data TBs conveyed in the PDSCH transmission in Cell#2.

In a second case, UE 114 detects a DL DCI format that schedules a PDSCHtransmission in Cell#7 and includes a cell-domain counter DAI fieldhaving a value V_(DAI) ^(DL-CT)=3 2344. UE 114 fails to detect DL DCIformats scheduling PDSCH transmissions for Cell#2 2340, Cell#5 2342 andCell#9 2346. UE 114 also detects an UL DCI format scheduling a PUSCHtransmission in a SF where eNB 102 expects UE 114 to transmit HARQ-ACKin response to PDSCH transmissions in Cell#2, Cell#5, Cell#7, andCell#9, where the UL DCI format includes a cell-domain total DAI fieldhaving a value V_(DAI) ^(UL-C)=4 2350. Based on the values of V_(DAI)^(DL-C)=3 and V_(DAI) ^(UL-C)=4, UE 114 determines that UE 114 failed todetect 2 DL DCI formats scheduling PDSCH transmissions in cells withindex smaller than 7 (the index for Cell#7) and 1 DL DCI formatscheduling a PDSCH transmission in a cell with index larger than 7 andUE 114 generates a HARQ-ACK codeword of {NACK/DTX, NACK/DTX, x,NACK/DTX} 2360 for transmission in the PUSCH where ‘x’ is either ACK orNACK/DTX depending on a correct or incorrect detection of data TBsconveyed in the PDSCH transmission in Cell#7. Therefore with acombination of a cell-domain counter DAI field in DL DCI formatsscheduling PDSCH transmissions and a cell-domain total counter (thatcounts all DL DCI formats scheduling PDSCH transmissions in a SF) in anUL DCI format scheduling a PUSCH transmission, UE 114 can identify aHARQ-ACK payload and arrangement of HARQ-ACK information bits in acodeword in a manner that is same as expected by eNB 102.

In case of a SPS PUSCH transmission from UE 114, there is no UL DCIformat scheduling the SPS PUSCH transmission and UE 114 cannot obtain aVD value. Relying only on a cell-domain counter DAI field in DL DCIformat can result to UE 114 transmitting an incorrect HARQ-ACK payloadin the SPS PUSCH as UE 114 can fail to detect DL DCI formats schedulingPDSCH transmissions in cells with larger indexes than a largest index ofa cell where UE 114 detects a DL DCI format. A first alternative is forUE 114 to transmit HARQ-ACK information for all configured cells. Asecond alternative is to rely on eNB 102 to resolve a HARQ-ACK payloadambiguity, for example as described in FIG. 22. A third alternative isto devise means for circumventing a HARQ-ACK payload ambiguity problem.

A first approach for the third alternative is to include a forwardrelative counter DAI field or a total DAI field, in addition to acell-domain counter DAI field, in DL DCI formats as was previouslydescribed in FIG. 14 or FIG. 15, respectively.

A second approach for the second alternative is for UE 114 to includeinformation for a number of received PDSCH transmissions together with,but separately encoded, the HARQ-ACK information. The second approachcan be conditioned on UE 114 multiplexing HARQ-ACK information in aPUSCH transmission that is not scheduled by an UL DCI format. The eNB102 can first decode an indicator field with value I_(rx) transmitted byUE 114 and indicating a number of PDSCH transmissions (or a number of DLDCI formats) UE 114 received. Based on that information, eNB 102 candetermine a HARQ-ACK information payload transmitted by UE 114 andaccordingly decode HARQ-ACK information and data information in thePUSCH. For example, an indicator field can include 2 bits where amapping of the 2 bits can be as in Table 6 by replacing V_(DAI) ^(UL-C)with I_(rx) and replacing ‘transmissions’ with ‘receptions’.

FIG. 24 illustrates a method for a UE to transmit HARQ-ACK informationby indicating a number of detected DL DCI formats according to thisdisclosure.

UE 114 determines a number of received PDSCHs (or, equivalently by alsoaccounting for SPS PDSCH release, a number of detected DL DCI formats)and generates and encodes an indicator for the number 2410. UE 114 alsogenerates and encodes, separately than the indicator, HARQ-ACKinformation bits for respective received PDSCH receptions 2420. UE 114multiplexes and transmits to eNB 102 the indicator codeword and aHARQ-ACK codeword in a same channel (PUSCH or PUCCH) 2430. The eNB 102receives the channel that conveys the indicator codeword and theHARQ-ACK codeword 2440. The eNB 102 decodes the indicator codeword toobtain a number of PDSCH transmissions that UE 114 received anddetermine a payload for the HARQ-ACK codeword 2450. Based on thedetermined payload for the HARQ-ACK codeword, eNB 102 decodes theHARQ-ACK codeword to obtain the HARQ-ACK information bits 2460.

For a TDD system, a DAI field with value V_(DAI) ^(UL-CT) in an UL DCIformat scheduling a PUSCH transmission can provide a total number ofPDSCH transmissions (or DL DCI format transmissions by including SPSPDSCH release) over both a cell domain and a time domain or,equivalently, the DAI field can provide a total number of PDSCHtransmissions over all cells and over all SFs of a bundling window(cell/time-domain DAI). A mapping for a value V_(DAI) ^(UL-CT) of theDAI field can be as in Table 6 by replacing V_(DAI) ^(UL-C) with V_(DAI)^(UL-CT) and considering PDSCH transmissions over the entire bundlingwindow.

A first alternative for determining an arrangement of HARQ-ACKinformation bits in a codeword is for UE 114 to use a value of a DAIfield in an UL DCI format scheduling a PUSCH transmission, a valueV_(DAI) ^(DL-C) of a cell-domain counter DAI field, and a valueV_(DAI,T) ^(DL-T) of a time-domain total DAI field in DL DCI formatsscheduling PDSCH transmissions in configured cells and SFs of a bundlingwindow. A counter DAI field provides a relative counter of a respectiveDL DCI format according to an index of a cell with a respective PDSCHtransmission. A total DAI field in a DL DCI format provides a totalcounter for DL DCI formats scheduling PDSCH transmissions in all cellsand in all previous SFs and a current SF of a bundling window. Using avalue V_(DAI) ^(UL-CT) of a DAI in an UL DCI format, UE 114 candetermine whether UE 114 failed to detect some DL DCI formats,particularly in SFs of a bundling window after a last SF of the bundlingwindow where UE 114 detects a DL DCI format. Using V_(DAI) ^(DL-C), UE114 can determine whether UE 114 failed to detect one or more DL DCIformats scheduling PDSCHs in cells with smaller indexes than an index ofa cell where UE 114 detects a DL DCI format that includes V_(DAI)^(DL-C) and schedules a PDSCH transmission in the cell in a SF. UsingV_(DAI,T) ^(DL-T), UE 114 can determine whether UE 114 failed to detectone or more DL DCI formats scheduling PDSCH transmissions in cells withlarger indexes than an index of a cell where UE 114 detects a DL DCIformat that includes V_(DAI,T) ^(DL-T) and schedules a PDSCHtransmission in the cell in a SF of a bundling window and also determinewhether UE 114 failed to detect one or more DL DCI formats schedulingPDSCH transmissions in cells in previous SFs of the bundling window.

FIG. 25 illustrates a determination and arrangement of HARQ-ACKinformation in a PUSCH using a counter DAI value and a total DAI valuein a DL DCI format scheduling a PDSCH transmission and a DAI value in anUL DCI format scheduling a PUSCH transmission for a TDD system accordingto this disclosure.

UE 114 is configured by eNB 102 for PDSCH transmissions in ten cells ofa TDD system where a bundling window size includes four SFs. In a firstSF, SF#0 2510, eNB 102 transmits to UE 114 three DL DCI formatsscheduling respective PDSCH transmissions in Cell#2, Cell#5, and Cell#7.A cell-domain counter DAI in a respective DL DCI format has a valueV_(DAI) ^(DL-C)=1 for Cell#2, a value V_(DAI) ^(DL-C)=2 for Cell#5, anda value V_(DAI) ^(DL-C)=3 for Cell#7 and a total DAI in each of thethree DL DCI formats has a value V_(DAI,T) ^(DL-T)=3. In a second SF,SF#1 2520, eNB 102 transmits to UE 114 three DL DCI formats schedulingrespective PDSCH transmissions in Cell#3, Cell#6, and Cell#7. Acell-domain counter DAI in a respective DL DCI format has a valueV_(DAI) ^(DL-C)=1 for Cell#3, a value V_(DAI) ^(DL-C)=2 for Cell#6, anda value V_(DAI) ^(DL-C)=3 for Cell#7 and a total DAI in each of thethree DL DCI formats has a value V_(DAI,T) ^(DL-T)=6. In a third SF,SF#2 2530, eNB 102 transmits to UE 114 two DL DCI formats schedulingrespective PDSCH transmissions in Cell#5, and Cell#7. A cell-domaincounter DAI in a respective DL DCI format has a value V_(DAI) ^(DL-C)=1for Cell#5 and a value V_(DAI) ^(DL-C)=2 for Cell#7 and a total DAI ineach of the two DL DCI formats has a value V_(DAI,T) ^(DL-T)=8. In afourth SF, SF#3 2540, eNB 102 transmits to UE 114 two DL DCI formatsscheduling respective PDSCH transmissions in Cell#3 and Cell#7. Acell-domain counter DAI in a respective DL DCI format has a valueV_(DAI) ^(DL-C)=1 for Cell#3 and a value V_(DAI) ^(DL-C)=2 for Cell#7and a total DAI in each of the three DL DCI formats has a valueV_(DAI,T) ^(DL-T)=10.

In SF#0 2510, UE 114 detects the first and third DL DCI formats andfails to detect the second DL DCI format. From the values C_(DAI)^(DL-C)=1 and V_(DAI) ^(DL-C)=3 of the cell-domain counter DAI in thetwo detected DL DCI formats in SF#0, UE 114 determines that UE 114failed to detect a DL DCI format for a cell with index larger than 2 andsmaller than 7. From the value V_(DAI,T) ^(DL-T)=3 of the total DAI inSF#0, UE 114 determines that UE 114 did not fail to detect any other DLDCI format. Therefore, UE 114 can determine and arrange HARQ-ACKinformation bits in response to receptions or absence of receptions ofPDSCH transmissions scheduled by DL DCI formats transmitted in SF#0.

In SF#1 2520, UE 114 detects the first and second DL DCI formats andfails to detect the third DL DCI format. From the values V_(DAI)^(DL-C)=1 and V_(DAI) ^(DL-C)=2 of the cell-domain counter DAI in thetwo detected DL DCI formats in SF#1, UE 114 determines that UE 114 didnot fail to detect any DL DCI format for a cell with index smaller than6. From the value V_(DAI,T) ^(DL-T)=6 of the total DAI in SF#1, UE 114determines that UE 114 failed to detect a DL DCI format and, using thevalue of the cell-domain counter DAI field in the DL DCI format forCell#6, UE 114 determines that the DL DCI format that UE 114 failed todetect is for a cell with index larger 6. Therefore, UE 114 candetermine and arrange HARQ-ACK information bits in response toreceptions or absence of receptions of PDSCH transmissions scheduled byDL DCI formats transmitted in SF#1.

In SF#2 2530, UE 114 detects both the first and second DL DCI formats.From the values V_(DAI) ^(DL-C)=1 and V_(DAI) ^(DL-C)=2 of thecell-domain counter DAI in the two detected DL DCI formats in SF#2, UE114 determines that UE 114 did not fail to detect any DL DCI format fora cell with index smaller than 7. From the value V_(DAI,T) ^(DL-T)=8 ofthe total DAI in SF#2, UE 114 determines that UE 114 did not fail todetect a DL DCI format for a cell with index larger than 7. Therefore,UE 114 can determine and arrange HARQ-ACK information bits in responseto receptions or absence of receptions of PDSCH transmissions scheduledby DL DCI formats transmitted in SF#2.

In SF#3 2540, UE 114 fails to detect both the first and second DL DCIformats. From the value V_(DAI) ^(UL-CT)=10 of the cell/time-domaintotal DAI in the UL DCI format scheduling a PUSCH transmission and fromthe determinations in previous SFs of the bundling window, UE 114 candetermine that UE 114 failed to detect two DL DCI formats in SF#3.Therefore, UE 114 can determine and arrange HARQ-ACK information bits inresponse to receptions or absence of receptions of PDSCH transmissionsscheduled by DL DCI formats transmitted in SF#4.

For brevity, in the following, a cell/time-domain relative counter DAIis referred to as counter DAI and a time-domain total counter DAI isreferred to as total DAI.

A second alternative for determining an arrangement of HARQ-ACKinformation bits in a codeword is for UE 114 to use a value of a DAIfield in an UL DCI format scheduling a PUSCH transmission and a valueV_(DAI) ^(DL-CT) of a counter DAI field in DL DCI format schedulingPDSCH transmissions in configured cells and SFs of a bundling window. Acounter DAI field in a DL DCI format scheduling a PDSCH transmission ina cell can provide a relative counter for DL DCI formats schedulingPDSCH transmissions in all cells and in all previous SFs and for cellindexes up to the index of the cell in a current SF of a bundlingwindow. Using V_(DAI) ^(UL-CT), UE 114 can determine whether UE 114failed to detect some DL DCI formats scheduling PDSCH transmissions,particularly in SFs of a bundling window after a last SF of the bundlingwindow where UE 114 detects a DL DCI format scheduling a PDSCHtransmission.

FIG. 26 illustrates a determination and arrangement for a HARQ-ACKinformation payload transmission in a PUSCH using a counter DAI value ina DL DCI format scheduling a PDSCH transmission and a DAI value in an ULDCI format scheduling a PUSCH transmission for a TDD system according tothis disclosure.

UE 114 is configured by eNB 102 for PDSCH transmissions in ten cells ofa TDD system where a bundling window size includes four SFs. In a firstSF, SF#0 2610, eNB 102 transmits to UE 114 three DL DCI formatsscheduling respective PDSCH transmissions in Cell#2, Cell#5, and Cell#7.A counter DAI in a respective DL DCI format has a value V_(DAI)^(DL-CT)=1 for Cell#2, a value V_(DAI) ^(DL-CT)=2 for Cell#5, and avalue V_(DAI) ^(DL-CT)=3 for Cell#7. In a second SF, SF#1 2620, eNB 102transmits to UE 114 three DL DCI formats scheduling respective PDSCHtransmissions in Cell#3, Cell#6, and Cell#7. A counter DAI in arespective DL DCI format has a value V_(DAI) ^(DL-CT)=4 for Cell#3, avalue V_(DAI) ^(DL-CT)=5 for Cell#6, and a value V_(DAI) ^(DL-CT)=6 forCell #7. In a third SF, SF#2 2630, eNB 102 transmits to UE 114 two DLDCI formats scheduling respective PDSCH transmissions in Cell#5, andCell#7. A counter DAI in a respective DL DCI format has a value V_(DAI)^(DL-CT)=7 for Cell#5 and a value V_(DAI) ^(DL-CT)=8 for Cell#7. In afourth SF, SF#3 2640, eNB 102 transmits to UE 114 two DL DCI formatsscheduling respective PDSCH transmissions in Cell#3 and Cell#7. Acounter DAI in a respective DL DCI format has a value V_(DAI) ^(DL-CT)=9for Cell#3 and a value V_(DAI) ^(DL-CT)=10 for Cell#7.

In SF#0 2610, UE 114 detects the first and third DL DCI formats andfails to detect the second DL DCI format. From the values V_(DAI)^(DL-CT)=1 and V_(DAI) ^(DL-CT)=3 of the counter DAI in the two detectedDL DCI formats in SF#0, UE 114 determines that UE 114 failed to detect aDL DCI format for a cell with index larger than 2 and smaller than 7.Therefore, UE 114 can determine and arrange HARQ-ACK information bits as{x, NACK/DTX, x}, where ‘x’ represents either an ACK or a NACK/DTX, inresponse to receptions or absence of receptions of PDSCH transmissionsscheduled by DL DCI formats transmitted in SF#0.

In SF#1 2620, UE 114 detects the first and second DL DCI formats andfails to detect the third DL DCI format. From the values V_(DAI)^(DL-CT)=4 and V_(DAI) ^(DL-CT)=5 of the counter DAI in the two detectedDL DCI formats in SF#1, UE 114 determines that UE 114 did not fail todetect any other DL DCI format in SF#0. For SF#0 and SF#1, UE 114 candetermine and arrange HARQ-ACK information bits as {x, NACK/DTX, x, x,x}.

In SF#2 2630, UE 114 detects both the first and second DL DCI formats.From the value V_(DAI) ^(DL-CT)=7 of the counter DAI in the detected DLDCI format for Cell#5 in SF#2, UE 114 determines that UE 114 failed todetect a DL DCI format in SF#1 for a cell with larger index than Cell#6or in SF#2 with a cell with smaller index than Cell#5. From the valueV_(DAI) ^(DL-CT)=8 of the counter DAI in the detected DL DCI format forCell#7 in SF#2, UE 114 determines that UE 114 did not fail to detect aDL DCI format in SF#2 for a cell with smaller index than Cell#7. ForSF#0, SF#1, and SF#2, UE 114 can determine and arrange HARQ-ACKinformation bits as {x, NACK/DTX, x, x, x, NACK/DTX, x, x}.

In SF#3 2640, UE 114 fails to detect both the first and second DL DCIformats. From the value V_(DAI) ^(UL-CT)=10 of the UL DAI in the UL DCIformat scheduling a PUSCH transmission and from the determinations inprevious SFs of the bundling window, UE 114 can determine that UE 114failed to detect two DL DCI formats for cells with larger index thanCell#7 in SF#2 or for any cells in SF#3. For SF#0, SF#1, SF#2, and SF#3,UE 114 can determine and arrange HARQ-ACK information bits as {x,NACK/DTX, x, x, x, NACK/DTX, x, x, NACK/DTX, NACK/DTX}. Therefore, UE114 can determine and arrange the HARQ-ACK information bits in responseto receptions or absence of receptions of PDSCH transmissions scheduledby DL DCI formats transmitted in all SFs of a bundling window.

It can be observed that a functionality of a DAI value, V_(DAI)^(UL-CT), in an UL DCI format is same as a functionality of a total DAIvalue, V_(DAI,T) ^(DL-T), in a DL DCI format. When eNB 102 transmits DLDCI formats to UE 114 in a number of SFs within a bundling window,unless UE 114 fails to detect all DL DCI formats in a last SF from thenumber of SFs (error case), V_(DAI,T) ^(DL-T) is same as V_(DAI)^(UL-CT) and, as previously described, a use of a DAI in an UL DCIformat can be omitted. A use of a DAI value in an UL DCI format can alsobe omitted when UE 114 transmits HARQ-ACK codeword in a PUCCH in a sameSF where UE 114 transmits a PUSCH scheduled by an UL DCI format thatincludes an UL DAI value. When an UL DAI field already exists in UL DCIformats, as in case of a TDD system (see also REF 2 and REF 3), aninterpretation of the UL DAI field can be different depending on whetherUE 114 is configured with up to 5 DL cells or with more than 5 DL cells.In the former case, a functionality of the UL DAI field can be asdescribed in REF 2 and REF 3. In the latter case, a functionality of theUL DAI field can be same as for a total DAI field in a DL DCI format andUE 114 can apply a same mechanism for determining a HARQ-ACK codewordfor transmission in a PUCCH and for transmission in a PUSCH. For a SPSPUSCH transmission or for a non-adaptive (not scheduled by an UL DCIformat) retransmission of a data TB in a PUSCH, UE 114 determines a sameHARQ-ACK codeword for transmission in a PUSCH or in a PUCCH using valuesV_(DAI) ^(DL-CT) of counter DAI fields and values V_(DAI,T) ^(DL-T) oftotal DAI fields in DL DCI formats. A same determination for a HARQ-ACKcodeword can also apply when a PUSCH transmission is scheduled by an ULDCI format or, to protect against the error case, the UL DAI field valueV_(DAI) ^(UL-CT) replaces the total counter DAI value V_(DAI,T) ^(DL-T)in determining the HARQ-ACK codeword while using a same mechanism forthe determination as for transmission in a PUCCH.

Allocation of Resources for HARQ-ACK Transmission in a PUSCH

In Equation 2, a number of REs, M_(RE) ^(req), required for multiplexingHARQ-ACK information in a PUSCH depends on a MCS for an initial data TBtransmission, through the term

${M_{sc}^{{{PUSCH}\text{-}{initial}}\;} \cdot {N_{symb}^{{PUSCH}\text{-}{initial}}/{\sum\limits_{r = 0}^{C - 1}K_{r}}}},$on a HARQ-ACK information payload O_(HARQ-ACK) and on an offsetβ_(offset) ^(PUSCH) that intents to decouple a data information BLERfrom a HARQ-ACK information BLER. For a given HARQ-ACK payload, aHARQ-ACK BLER depends on a coding method used to encode the HARQ-ACKinformation bits. For example, for a RM code, a coding gain can be suchM_(RE) ^(req) increases linearly with O and therefore using a singleβ_(offset) ^(PUSCH) value can be sufficient. However, for a TBCC, acoding gain can be non-linear with O and UE 114 can be configuredseveral β_(offset) ^(PUSCH) values for respective values of O therebymaking β_(offset) ^(PUSCH) a function of O. For example, for HARQ-ACKpayloads up to 128 bits and use of TBCC for HARQ-ACK payloads above 22bits, eNB 102 can configure three β_(offset) ^(PUSCH) values to UE 114;a first value, β_(offset) ^(PUSCH)(O₁), for use with HARQ-ACK payloadsbetween 23 bits and 60 bits, a second value, β_(offset) ^(PUSCH) (O₂),for use with HARQ-ACK payloads between 61 bits and 96 bits, and a thirdvalue, β_(offset) ^(PUSCH)(O₃), for use with HARQ-ACK payloads between97 bits and 128 bits.

A coarser or a finer granularity for a range of HARQ-ACK payloads can beachieved by configuring, respectively, a smaller number or a largernumber of β_(offset) ^(PUSCH) values. When eNB 102 configures a singleβ_(offset) ^(PUSCH) value to UE 114 for HARQ-ACK payloads encoded by aTBCC that range from O₁ bits to O₂ bits, where for example O₁=23 andO₂=128, there can be at least two approaches for eNB 102 to select theβ_(offset) ^(PUSCH) value. In a first approach, eNB 102 can select theβ_(offset) ^(PUSCH) value as the one providing a value of M that canachieve a desired BLER for a HARQ-ACK information payload near themid-point of O₁ and O₂. In a second approach, in order to ensure adesired BLER at the expense of occasional unnecessary use of resourcesfor HARQ-ACK transmission in a PUSCH, eNB 102 can select O₁ as areference payload for determining a β_(offset) ^(PUSCH) value sincecoding gains increase as an HARQ-ACK payload increases. Even when eNB102 configures UE 114 with a single β_(offset) ^(PUSCH) value when UE114 uses a TBCC to encode HARQ-ACK information, eNB 102 separatelyconfigures UE 114 a first β_(offset) ^(PUSCH) value for use in case ofRM coding or repetition coding (for payloads up to 22 bits) and a secondβ_(offset) ^(PUSCH) value for use in case of TBCC (for payloads above 22bits).

Although the present disclosure has been described with exampleembodiments, various changes and modifications may be suggested to oneskilled in the art. It is intended that the present disclosure encompasssuch changes and modifications that fall within the scope of theappended claims.

What is claimed is:
 1. A method comprising: receiving control signalingthat conveys downlink control information (DCI) formats, wherein: eachof the DCI formats indicates scheduling for either a reception for aphysical downlink shared channel (PDSCH) or a release for asemi-persistently scheduled (SPS) PDSCH in a transmission time interval(TTI) from a number of TTIs and on a cell from a number of cells, eachTTI has a TTI index and each cell has a cell index, each of the DCIformats is associated with a cell index and with a TTI index for arespective PDSCH reception or SPS PDSCH release, each of the DCIformats, when received in a user equipment (UE) specific search space,includes a counter downlink assignment indicator (DAI) field having avalue that counts DCI formats, first across cells from the number ofcells according to an ascending cell index and then across TTIs from thenumber of TTIs according to an ascending TTI index, until the index ofthe TTI and the index of the cell associated with the DCI format, andeach of the DCI formats, when received in the UE-specific search space,further includes a total DAI field having a value that counts DCIformats across all cells and across TTIs from the number of TTIsaccording to an ascending TTI index until the index of the TTIassociated with the DCI format; generating acknowledgement informationbits in response to receiving the one or more PDSCHs or the one or moreSPS PDSCH releases; and transmitting the acknowledgement informationbits.
 2. The method of claim 1 wherein: each of the DCI formats, whenreceived in a non-UE specific search space, includes the counter DAIfield and does not include the total DAI field when operating in a timedivision duplex mode, and each of the DCI formats, when received in anon-UE specific search space, does not include any of the counter DAIfield or the total DAI field when operating in a frequency divisionduplex mode.
 3. The method of claim 1, wherein a TTI index for a DCIformat reception is different than the TTI index for the PDSCH receptionthat is scheduled by the DCI format.
 4. The method of claim 1, whereinthe acknowledgement information bits include information for failure ofa DCI format reception, information for a reception of a DCI formatscheduling SPS PDSCH release, information for a correct reception ofdata information in a PDSCH, or information for incorrect reception ofdata information in a PDSCH.
 5. The method of claim 1, furthercomprising: transmitting the acknowledgement information bits usingReed-Muller coding in a physical uplink control channel (PUCCH) having afirst format when a number of the acknowledgement information bits isnot more than 22; and transmitting the acknowledgement information bitsusing tail biting convolutional coding in a PUCCH having a second formatwhen the number of the acknowledgement information bits is more than 22.6. The method of claim 1, further comprising receiving additionalcontrol signaling that conveys a DCI format that indicates schedulingfor a transmission of a physical uplink shared channel (PUSCH) andincludes a value for a DAI field that replaces the value of the totalDAI field.
 7. The method of claim 1, further comprising: receiving a SPSPDSCH; generating an acknowledgement information bit in response toreceiving the SPS PDSCH; and transmitting the acknowledgementinformation bit in a last location of the acknowledgement informationbits.
 8. A user equipment (UE) comprising: a receiver configured toreceive control signaling that conveys downlink control information(DCI) formats, wherein: each of the DCI formats indicates scheduling foreither a reception for a physical downlink shared channel (PDSCH) or arelease for a semi-persistently scheduled (SPS) PDSCH in a transmissiontime interval (TTI) from a number of TTIs and on a cell from a number ofcells, each TTI has a TTI index and each cell has a cell index, each ofthe DCI formats is associated with a cell index and with a TTI index fora respective PDSCH reception or SPS PDSCH release, each of the DCIformats, when received in a user equipment (UE) specific search space,includes a counter downlink assignment indicator (DAI) field having avalue that counts DCI formats, first across cells from the number ofcells according to an ascending cell index and then across TTIs from thenumber of TTIs according to an ascending TTI index, until the index ofthe TTI and the index of the cell associated with the DCI format, andeach of the DCI formats, when received in the UE-specific search space,further includes a total DAI field having a value that counts DCIformats across all cells and across TTIs from the number of TTIsaccording to an ascending TTI index until the index of the TTIassociated with the DCI format; a controller configured to generateacknowledgement information bits in response to the reception of the oneor more PDSCHs or the one or more SPS PDSCH releases; and a transmitterconfigured to transmit the acknowledgement information bits.
 9. The UEof claim 8 wherein: each of the DCI formats, when received in a non-UEspecific search space, includes the counter DAI field and does notinclude the total DAI field when operating in a time division duplexmode, and each of the DCI formats, when received in a non-UE specificsearch space, does not include any of the counter DAI field or the totalDAI field when operating in a frequency division duplex mode.
 10. The UEof claim 8, wherein a TTI index for a DCI format reception is differentthan the TTI index for the PDSCH reception that is scheduled by the DCIformat.
 11. The UE of claim 8, wherein the acknowledgement informationbits include information for failure of a DCI format reception,information for a reception of a DCI format scheduling SPS PDSCHrelease, information for a correct reception of data information in aPDSCH, or information for incorrect reception of data information in aPDSCH.
 12. The UE of claim 8, wherein the transmitter is configured to:transmit the acknowledgement information bits using Reed-Muller codingin a physical uplink control channel (PUCCH) having a first format whena number of the acknowledgement information bits is not more than 22,and transmit the acknowledgement information bits using tail bitingconvolutional coding in a PUCCH having a second format when the numberof the acknowledgement information bits is more than
 22. 13. The UE ofclaim 8, wherein the receiver is configured to receive additionalcontrol signaling that conveys a DCI format that indicates schedulingfor a transmission of a physical uplink shared channel (PUSCH) andincludes a value for a DAI field that replaces the value of the totalDAI field.
 14. The UE of claim 8, wherein: the receiver is configured toreceive a SPS PDSCH, the controller is configured to generate anacknowledgement information bit in response to receiving the SPS PDSCH,and the transmitter is configured to transmit the acknowledgementinformation bit in a last location of the acknowledgement informationbits.
 15. A base station comprising: a transmitter configured totransmit control signaling that conveys downlink control information(DCI) formats, wherein: each of the DCI formats indicates scheduling foreither a transmission for a physical downlink shared channel (PDSCH) ora release for a semi-persistently scheduled (SPS) PDSCH in atransmission time interval (TTI) from a number of TTIs and on a cellfrom a number of cells, each TTI has a TTI index and each cell has acell index, each of the DCI formats is associated with a cell index andwith a TTI index for a respective PDSCH transmission or SPS PDSCHrelease, each of the DCI formats, when received in a user equipment (UE)specific search space, includes a counter downlink assignment indicator(DAI) field having a value that counts DCI formats, first across cellsfrom the number of cells according to an ascending cell index and thenacross TTIs from the number of TTIs according to an ascending TTI index,until the index of the TTI and the index of the cell associated with theDCI format, and each of the DCI formats, when received in theUE-specific search space, further includes a total DAI field having avalue that counts DCI formats across all cells and across TTIs from thenumber of TTIs according to an ascending TTI index until the index ofthe TTI associated with the DCI format; and a receiver configured toreceive acknowledgement information bits in response to the transmissionof the one or more PDSCHs or of the one or more SPS PDSCH releases. 16.The base station of claim 15, wherein the receiver is configured to:receive the acknowledgement information bits using tail bitingconvolutional decoding, that includes a cyclic redundancy check (CRC)result, according to a first number of acknowledgement information bits,and receive the acknowledgement information bits using tail bitingconvolutional decoding according to a second number of acknowledgementinformation bits that is smaller than the first number ofacknowledgement information bits when the CRC result is false.
 17. Thebase station of claim 15 wherein: each of the DCI formats, when receivedin a non-UE specific search space, includes the counter DAI field anddoes not include the total DAI field when operating in a time divisionduplex mode, and each of the DCI formats, when received in a non-UEspecific search space, does not include any of the counter DAI field orthe total DAI field when operating in a frequency division duplex mode.18. The base station of claim 15, wherein the acknowledgementinformation bits include information for failure of a DCI formatreception, information for a reception of a DCI format scheduling SPSPDSCH release, information for a correct reception of data informationin a PDSCH, or information for incorrect reception of data informationin a PDSCH.
 19. The base station of claim 15, wherein the receiver isconfigured to: receive the acknowledgement information bits usingReed-Muller decoding in a physical uplink control channel (PUCCH) havinga first format when a number of the acknowledgement information bits isnot more than 22, and receive the acknowledgement information bits usingtail biting convolutional decoding in a PUCCH having a second formatwhen the number of the acknowledgement information bits is more than 22.20. The base station of claim 15, wherein: the transmitter is configuredto transmit a SPS PDSCH, and the receiver is configured to receive anacknowledgement information bit in a last location of theacknowledgement information bits.